+1 on North Dallas Aquarium. I was at The Fish Gallery on Greenville Avenue (mid Dallas) today and the FW fish/plant selection was small and uninteresting (has been for many months - though their Saltwater selection seems to be better. Honestly, for as big as Dallas is I have yet to be impressed by many of the stores here but Dallas North comes close. Also note this is just my opinion
I hope she has a fun trip!