It will not matter how much “da’wah” you make; unless the other person is him/herself not willing there is nothing you can do, however, do try to find the root cause of her conversion. I do not believe in superficial invitations that are characteristic of today’s “da’wah” …
Did she see something good in the conduct of your Hindu friend that had a lasting impact on her?
I know of a gentleman who converted to Islam only based on the conduct of our family-friends and no other influence.