&gt;I have no conclusive proof that she’s fucked anyone but...

There is more to infidelity than just allowing somebody to stick their dick in her, such as....

&gt;seriously flirting, telling guys she loves them, and actively trying to  link with people from Instagram (who are clearly trying to fuck). She  even goes as far as to refer to me as a family friend.

..this.. This is infidelity.

&amp;#x200B;

Do you really need our advice here? Be thankful she has exposed her true nature so early in your relationship, so you don't have to spend the best years of your life being attached to the wrong person.