Bro,
Marriage is not fun. It is serious relationship.
First of all if she wants to marry you. She must get divorce from her previous husband .
What if the husband loves her more than u and says he will convert to Islam yes if he says no then she is free to marry somebody else but no cheating or manoeuvring of situations. Everything to be crystal clear
If u Can u or she speak to his husband and request to him to divorce her.the situation will be easy n peaceful.
It is possible in real love.
The best advise
Get yourself into other activities and forget it it is temporary phase