Potential Supervisor Said She Will Contact References- No Response
I know she contacted one already, and I know they gave a great feedback, but it's been more than two months now without hearing from her. Should I contact her and ask if she needs any extra info or wait?


Definitely contact her! There was genuine interest between you and you have nothing to lose, everything to gain.

It is easy to fall under the impression that contacting professors/supervisors is "a bother", and that you are being annoying by doing so. However, I have found that the opposite is often true: some supervisors use whether you follow up as a way of gauging your true interest in the position. So although I don't know the full context, I think waiting two months was not the best. Worst case scenario, she has now assumed you aren't interested anymore.

As long as you are not officially admitted, I would therefore follow up ASAP to make sure she knows:


That you are still interested
That you are waiting to hear from her (i.e., she has to do something), and what it is she has to do


Depending on her response you can follow up repeatedly as needed, for instance:


If she doesn't respond I would follow up again in about 1 week
If she responds indicating some delay (e.g., she is waiting for a response from reference X), follow up again depending on the expected delay, maybe 2 weeks or so


Also, you can directly talk to your other reference to see if they have been contacted by her. That could also help in case the reference is causing the delay.