I have a friend that I am starting to not trust.I feel like she is using me to get to my other friend because of the people my friend knows.I warned my friend about the friend I have the trust issue with.I told her that I think my friend is using me to get to her for her connections.What I find not normal is now my friend is starting to talk to the friend I don't trust online.Is this normal? I really don't want to lose the friend that I do trust.

You have no right to tell your friends who they can and cannot talk to. It's not your business.
Maybe she just wants attention or isn't that great a friend? I don't really know what the issue is tbh. Seems very school girlish tbh.
You really might have to consider... her friendship with the person you distrust may have nothing to do with you whatsoever. Sometimes it's not about you.
Sometimes you have friends who dislike - or even hate - your other friends.
What's hard is when you have friends who decide "well if you're friends with so-and-so it means you don't care about me!" as if you're suppose to ditch people you like just to sooth someone else's ego.
Cos if you really like your friends you wouldn't be giving them ultimatums like that. That's high-school drama bs