Verification against EU law as a student

Hello everyone!

I am a non-EU resident in the Netherlands, currently finishing my MSc program. I am in a relationship with a Bulgarian citizen, who is also a MSc student, and we have been together for 3 years, while living at the same address. We decided to look into verification against EU law but there are a few things that remain unclear.

Firstly, my partner has BSN and she has lived in NL for already 5 years, so does she still need to register with IND? Secondly, I have read many times that during the waiting period a non-EU applicant will be allowed to work, however, I have also read that sometimes it was not the case. This is a crucial point for me, as I will be basically switching from a student visa to a partner visa, skipping an orientation year visa (which allows me to work freely). If the process will indeed take ~6 months, then I definitely need to be able to work during this time, so does somebody know what does this permission depend on? Thirdly, since my partner is a student, she does not need to provide any proof of income, is it correct? She has savings and receives also money from her parents monthly but we are not sure whether proving that is necessary at all. And finally, we are not registered as partners, so we are thinking about the proof we can provide to show that we are in a relationship. We have so far rental contracts, Airbnbs, plane tickets, photos, is there something else that it could be relevant to provide and also in what quantities? We compiled a folder with like 40 photos but we think it is a bit too much haha. I would appreciate any help with any of these questions, thank you!!