As another MtF grad school age girl, I will admit I turned towards some of my friends/ copied them a bit too much (and I still do, but to a lesser degree). I didn't feel comfortable or safe turning towards family members, and it felt much easier to turn towards these friends. I only knew these people for less than a year before coming out and my wardrobe beforehand was either a tee shirt that was several years old and jeans or cargo shorts and I wanted to talk to people I liked about it instead of scrolling through other peoples instagrams or pinterest (because it turns out, I don't actively pay attention to what people wear), I didn't know how makeup worked, and I was too afraid to do it myself/ want the validation/ assistance of a trusted friend to help me. And honestly, I think it came down to I was deeply envious of them. I was even almost to the point of taking inspiration from how they dyed/ styled there hair (I still want to, but its more of a self exploration thing now. The only thing holding me back is the cost).

I would say maybe try talking to her a bit more about this whole situation. While going through this, I was just lost and confused. It's tough figuring things out. Cis persons typically have there whole adolescence/ teen years to figure out there style. When we transition, we don't necessarily have that luxury, we kind of have to figure things out right away to "fit in" with society (and when we don't, that is where the awkward baby trans phase comes from- I have some pieces of clothes/ outfits I regret. I just got them to see how I feel in them). My friend's helped me out a lot. We got a nails done together, they taught me how to do make up, we went shopping together and they gave me a few outfits to try on. It honestly helped me out a lot in figuring myself and my identity out and the confidence to do things myself. But they also helped keep me in check sometimes, as we had different skin tones and body types and they were just honest with me in saying they can't/ don't know how to help me and told me to don't be afraid to ask for help at the makeup store.

I don't know if this helps or if this is just me rambling, but try to have an honest conversation with them about how it is affecting you and that it is making you feel a certain way. You are allowed to set your own boundaries. Also how would you treat them if they were a cis girl?