Well, we don't know if the kid is a witch as of yet. What we "know", supposedly the vampire side should negate any ability to be a witch... BUT, with that being said, we ARE talking about a growing, aging, fetus--that is nearlly human like, but as we all know...very supernatural.
The ruleset has been thrown out the window for this little one. Nature has created, truly, a new species and we have no idea what nature has in mind for this baby or mother. She could be born in five months instead of nine; she could grow to 25 and stop aging, remaing immortal forever...or grow old and die like any other human, but be able to conceive with almost anyone (except I assume for full-blooded vampires). She definitely did come from a family of witches as her grandmother was one and her aunt was one before being transformed. So her being one, if nature so see fits, isn't surprising to me.
I know some have commented on the Davina time-travel idea, but another idea down that vein, at least in the notion that the baby is "related" to Davina is the fact that the witches were very tight lipped from day one about just what was causing their magical issues. What if the witches knew to some degree that the witch that was behind controlling them (I suspect they didn't know it was Davina until this last episode, however they did perform magic on the baby again--so there is no telling what they really did, as I don't buy the, "finding out the baby's sex", story realistic at all...why in the hell would you take a chance casting THAT spell?; I suspect something was "added on" that they didn't bother telling Hayely about--Hayely is WAY too trusting with that stuff...) belonged to a very specific family line.
With that information and the fact that they took Hayely out into the woods and performed quite a few magical spells on her all sorts of things could be going on with that baby. Since the town uses ancestral magic, for all we know they could've linked the baby directly to the family line that they thought the traitor was in, so if the traitor (Davina) ever tries to target said baby an equal and opposite amount of magical energy will form and either reflect her spell or cancel it all out. That is one scenario. They could've linked the baby to Davina herself in some fashion. The baby could even be the reincarnation of the sister that died to perform the spell to confirm if it "really is a hybrid baby". But, couldn't they have done THAT in the swamp. Something tells me the spell that was ACTUALLY cast was of a MUCH higher magnitude.
We still don't know if Davina can sense what type of magic (how the magic is being used) and though we know she can alert marcel to exceptional spikes of magic, she doesn't seem to be able to discern between small and major usages (like in Klaus's smoke screen plan). So it is still in the air as to how well Davina can even discern the magnitude of spells as well other than "small", moderate, and "gigantic"...
As for the baby. She for one thing IS a friend to nature, which should REALLY make people think. She is either a witch or something (which whether she is a witch or not I think this is still true) extremely special and as I said--and this IS true--something NEVER before seen on Earth. Something born from Darkness that even NOW nature excepts...essentially in my euyes meaning this is a child of "light". BTW, it could even be possible that is Julie doesn't plan on really bringing the "Original Pack" into the scene on either show, she COULD always create them however... What if this baby is an Original Pack member, the first, the eventual mother to her kind...? Besides anything else she may be, what if she is also this as well?
Until the baby is born, it will be too hard to figure out what she is and isn't. Those witches could've done ANYTHING to Hayely in that swamp. We don't have any idea what that child is--some of it's exisistence could be a "magical glamour". In fact, I wouldn't be surprised if it wasn't true.
But, if that baby IS the real deal and is a friend to nature, even the witches (even though they heard that extremely hostile and disturbing warning in Latin) have to recognize that if nature allows this "supposed" vampire to come onto holy ground, to be one with nature and possibly even be one of their own. Something extremely special is happening down there in that town of New Orleans and Klaus is too stupid to even realize it yet. The only one that seemed to even think about the real implications was Elijah, who I VERY much hate that he has been removed for several episodes.
The wolf coming up, as to show that perhaps the baby was being protected in some way--perhaps by nature itself--was very interesting. It makes me wonder what might happen if the baby or mother's life becomes truly endangered (especially the baby's).
PS- This is off topic but I want to say it. But if Klaus DOES take his siblings "out of commision" every other episode, it will get old really fast like it did on Vampire Diaries. But, especially on a show that is called "The Originals" that is VOID of "Originals", I think you all can understand what I mean by this.
What do you think?