She says, why do you want to hurry? Let's put the defense in December, then you can have several publications out till then.
I am thinking of asking directly, "What do you think about my PhD work? Are you not happy with my work and is that the reason you are delaying correcting my manuscripts? "
Will that be appropriate? What should I do and tell/ask her?
Yes, it is appropriate to ask her what is going on. This is your PhD and she has no right to delay it in the way that she is currently doing. As a supervisor, she is supposed to support you in finishing your thesis, and if she is not doing that, you have a good reason to complain about it.
I do not think that it is even important what she is thinking of your work. If she thinks that your work is bad, that would make it even more important to give you this kind of feedback. So that is not a good reason to not give you feedback, and I also think it's highly unlikely that this is the actual reason why.
I would simply argue with the facts. After 5 years of doing your PhD, you want to be finished soon. In order to do that, you need her to give feedback on the manuscripts. If she says "why the hurry" again, there are several things you can point out, for example:
But actually, the question is beside the point, because it is your decision, not hers, and that is not why you are talking to her. If she really tries to derail the conversation in this way, I would call her out on it. "I feel like you are avoiding the actual issue I am addressing here. I have waited for your feedback for 1.5 years now. I think this is clearly too long, and now that I am ready to finish my PhD, I really need that feedback. I can understand that you are busy, but I have the feeling that you are frequently giving my work a low priority. I do not know why you are doing this, but it is frustrating. I currently do not feel appropriately supervised by you."
Well okay, I might have a slightly confrontational nature, so take this with a grain of salt. But I think in such a case it is adequate to criticize her for the lack of supervision that you have experienced throughout your PhD.
A last tip would be to give her deadlines. Usually people prioritize things where they get a clear deadline, even if the deadline is arbitrary. In the best case scenario, you can tie the deadline to an actual milestone of your final phase of the PhD - like maybe you want to say that by the end of March, you want to be done with the actual research and only focus on structure and design of the thesis, so that the deadline for her would be somewhere in March.
I don't know the personalities here nor the way your advisor thinks about things, but, while I'd probably agree that she is wrong, she may, in fact, be trying to place you in as strong a position for your future as possible. Presumably she knows some things about your field and how to be a success starting out. I hope so, anyway. So, I wouldn't just assume that she is trying to obstruct you as the first estimation of what is happening. It could but the opposite, but you are in a better position to judge that than I.
But, you have a legitimate need to finish and move on with an expeditious schedule. And you can express that to her and get a sense of what your path is to an early completion.
Schedule a sit-down meeting in which you (a) let her know you want to be done ASAP and why that is, and (b) what you need to do to accomplish that.
Try to learn, in such a meeting, why she thinks delay is best, if that is actually what is happening. Try to get an honest evaluation of your work.
You will almost certainly want your advisor to be a supporter you in your early career, so try not to jeopardize that. You seldom win by fighting with your advisor.
You gotta fight for your interests. Mousing around will get you continue to being stepped on. The squeeky wheel gets the oil. Yeah Buffy is right, the little tinpots might walk on you if you fight them, but they walk on you a lot harder if you let them without squawking.
Personally I wouldn't ask for "feedback" but movement. Hand in papers that YOU THINK are ready to be submitted. That are how you would submit them as a PI. You should do this regardless, because why have your advisor review something that is not your best effort? So once they meet that bar, it's not hard to see just moving them right to the journals. Stat.
Same with the thesis defense. Just schedule it. What's the worst that can happen? You fail. So. It's a delay either way. So, just push the peanut. Make the cars crash.
As for the thesis, like Michael Schmidt, below, I didn't get any edits from my advisor (or really give him an opportunity). Gave him the doc 10 days before the defense (as was required by the rules). He whined a little, but I said, you're a committee member like the rest. You can fail me if it's not good enough. He didn't fail me...it was a good thesis and good research record. It would have been silly for him to do otherwise. [Of course if your research is not above average, this kind of hardball may not be as feasible.]
P.s. Hanging onto grad students for an extra year to get more papers out of them is a known trait of some professors. Gotta push back on that.
Normally, you both should have the interest to publish as soon as possible. If she doesn't hurry, she has other priorities. That your supervisor/professor has for weeks/months often no time to review your manusscripts is quite usual. But over a year sounds strange to alarming to me, you probably discussed the main statements/abstracts ot those manuscripts with her before writing them.
Other questions are the requirements of your faculty. Technically, you don't need in every country several articles published in peer-reviewed journals. It's your decision and responsibility to write and submit your thesis at some point to the faculty or wait for years for your supervisor. For instance, I didn't show my diploma thesis to my supervisor after writing it to review style and content, I know many students do this and some professors want it, but there are no standards and it had no negative outcome for me.
So, in your case, I would tell here what your timeline is, how much work is left, and when you want to submit your thesis. Making up stories in your mind she might not be happy with your research is a dead end...
