How can I marry a foreign National in India?

I am Indian and my girlfriend is Bangladeshi(both Hindu).We wish to marry under special marriage act but marriage officer of my jurisdiction asked for Aadhar card of the Bangladeshi girl for registering our marriage and also agreed to get her aadhar card done.Is it legal to make aadhar card before marriage???Will there be any problem in case of her visa and immigration process when she wants to visit her country?As of now Bangladeshi people are given visa and allowed immigration in India only after giving their 10 fingerprints.I am worried about this.