Love Tabitha, not mad keen on Jasmine and I don't know why as it is a pretty name I just don't like it. I think the two names look nice together though and I'm not averse to TJ as a nickname for when she's a stroppy teen.
I like both names independently, and I like the flow (three syllables followed by two) but Tabitha Jasmine... it's like one is country (Tabitha) and the other is city (Jasmine). They aren't a match "category"-wise. I agree with whoever said Tabitha was dreamy, it is. Sort of magical. Jasmine is a bit sharper somehow. Tabitha's sharper older cousin .