Valerie & Others:
Kindly and patiently consider my answer, please.
On one hand, I'm preop and will probably remain nonop. Upon reading this, many postoperatives are apt to shut down and disregard another word I say. I beg their attention on this matter.
On the other hand, I've done medical transcription and transcription QA/QC (Best of the Best) for nearly 15 years, so I know A LOT about this subject inasmuch as I've typed and/or reviewed THOUSANDS AND THOUSANDS of gynecological hospital reports over the years.
Chances are that hers is an isolated incident due to "enthusiastic thrusting" and nothing more than this. Surely, a postoperative tear can occur. Consider, please, that very-high-dose (relative to natal women) estrogen we take during transition softens our skin immensely from many of us. Skin tears are apt to occur much, much more easily than pretransition and, perchance, much more easily than in natral females because of estrogen's effects upon us.
My recommendation to ANY postoperative T-girl:
Get an annual well-woman examination complete with a pelvic bimanual examination and a sterile speculum examination by either a gynecologist or an internist who knows what they are doing with this matter.A postop T-girl to some extent is an anatomical woman now and, so, requires these exams yearly if not biannually. Actual biological women need closer attention than we do for a multitude of medical reasons beyond the scope of this post.
About your friend, Valerie:
Sure, going down a size in dilators may help. However, she REALLY should see a gynecologist and get an examination as mentioned above. Just my two-cents' worth. In this particular matter, I believe I'm well-qualified to offer said opinion.
My best to ALL you postoperative T-girls! Yeah, I'm kind of jealous. However, given my age and circumstances, going operative may not be in the cards such that the risks may outweigh the benefits in my particular case.
Hugs!

Lacey