I know kids may be used to fly (our are), but how long ago was your child sleeping 8 hours straight. At 2.5 years old it might be differene (on our last transatlantic flight back to Europe, my 2.5 yers old was just bragging with a massive smile and laughter that she wasn't sleepy... was still a good flight as we played with her and she was adorable, but being pregnant you might not be as awake ;-)
Anyway if you are ready for the long flight, south of Europe seems the best (imagine lisbon, faro, sevilla, grenada, sicily, ...)