Yes islamically its wrong... and so is bringing ur child into such circumstances
were desi children/people with call/bully her child when its older.
how is it wrong islamically..tomorrow if she shows you a nikkahnama noting that she infact was married to this guy or claims muttah/misyar type situation was there, which while I dont agre with seems to be sanctioned by the scholarly powers that be, then your 'islamically its wrong' argument goes out the window