PMSL - my 4yo is well advanced then, his speech is child-like but he gives long complex sentences and has a fairly full vocabulary. Haven't counted his words since just before his second birthday - over 200 words and 5-6 word sentences. At about 18m he was at the 2-3yo stage too. He's bright but not in the gifted league at all.

A gifted child will learn no matter what. Can you encourage other skills? Drawing is a great skill, but maybe you could encourage walking to the park, climbing, dancing, playing drums/piano... things outside her area of success, basically.