What should I do if she never validates my feelings?
We all need our feelings validated but where things become tricky is that this looks different for each of us. The key is, as always, communication but the art is to create a conversation that is based on co-exploration rather than sounding like blame.
A useful framework for this is the non-violent communication framework that guides you to use I-statements to state what you observe, how that makes you feel, what you need along with a suggestion for how to meet in the middle. Make sure to also ask her what she needs from you to further ensure that the conversation meets both your needs.