Wow! What a stupid thing to write!! LOL! I took it to mean 3-dimensional, but only after reading it three times. Sheesh.
I've been known to say equally stupid things!
I agree with most of the others - that was actually a compliment - she is looking forward to the day your REAL 8 year old comes to visit.
Agree with everyone else, 2D vs. 3D and the fat/flat rhyming. I'm sure the relative thought they were extremely witty! The key wording for me is "fat AGAIN" - that makes no sense if the relative were saying your daughter is currently fat, but a TON of sense, when you consider "flat" Stanley vs. a real person.