If she's an American citizen and travelling on a visa issued under her maiden name where the passport's amended name change is noted in the very same US passport, there will not be a major issue -- especially if the visa was also issued in her maiden name. At most the immigration officer might ask for some document to prove marriage and/or maiden or married name and even this is unlikely. [Marriage certificate is good enough in any event.]
Indian immigration doesn't really care about what name her ticket is under as long as one of the two names (either first or last) on the ticket is close to what is on the ticket and on passport. If the visa name and the passport names are way off with no documented, reasonable explanation -- apparently a non-issue in your case -- then there may be an issue.
I would be more concerned about the airline than Indian immigration ... and the airline is unlikely to cause an issue if the name change amendment is included in her passport.