If your boss put her in to position of supervising you or helping you etc then it doesn’t matter who has more credentials. In fact people often are placed in supervisory positions not due to credentials but other skills.

If you believe she isn’t placed in position to supervise you, then I’d ask your boss if she is your supervisor etc it could be that she is crossing boundaries but you don’t know what your supervisor told her to do.

I absolutely wouldn’t be confronting anyone but rather politely ask your boss ofbwhat are this girl’s responsibility in regards to you. Confronting anyone would make you look confrontational and can even cost you a job.

I know people who argue and complain in every job and they usually don’t last long on
the job so be careful