Love is the drive for community, to grow with another person or people in order to build something greater than yourselves. Infatuation and Passion can be expressions of love, but they are not love in-itself.
Infatuation in the absence of love is simply a desire for possession, a drive to make a person yours as though they're a resource to be harvested. Infatuated love can fade to pure possessiveness or boomer-esque disdain when the situation develops in a way that wasn't expected. To really love someone, you have to be prepared for them to change.
An easy example of this is when the love a parent has for their child fades when that child wishes to transition. True love would work through the change in order to value the person over their static "role" in the family structure.
In romantic love this can come in the form of pregnancy, increased dependence, increased independence, failing to contribute to the family economy, and a myriad of other reasons, some as simple as boredom when the New Relationship Energy fades off.
New Relationship Energy fueled by infatuation can mask a lot of incompatibilities, and when things fade you might find genuine feelings were for a person who only exists in your head. I believe this is what your friend is worried about.
I was actually in a similar situation as a teenager from which I moved on. If she's a lot more experienced than you she might be clocking incompatibilities that are inconsequential with you two being "just" friends, but could create drama when the NRE wears off.