she says her church would excommunicate her or something like that and she says she does not care she loves me but im afraid of the fact how wiill we get married
You're right. The pressure will pile up when you get married.
Ask her to live you you before marriage. If she will live with you then that might be a good sign, you can keep reminding her how you won't become a JW until hopefully she stops.
But if she won't live with you, then she is committed JW. She will pressure you once you are married.