I think the baby will either be Nik's or Stavros's baby. Why have Nik get involved in this if he isn't going to have something to do with it later? Nik gave a donation when Robin asked him to be a donor way back when so that makes sense.
I don't feel it has anything to do with Emily though because she's been dead way too long and I don't recall her ever putting, or having Eason to put, her eggs on ice.
As for IF this baby HAD been Em's, it would be easy to fight that Em was not a blood Q so no child of hers would have rights to ELQ stock.
For people saying they hope a 6 year old suffers over this, really? I think Emma shows more maturity than comments like that, anyday!