It varies. My son was really into colors and shapes, knew them all at 15 mo, sang his ABCs & counted to 20 shortly after, but only now is starting to recognize letters, numbers, and words. But he can jump, run, walk up & down stairs, throw a ball, walk on the balance beam, etc. really well, is potty trained, and does chores around the house, at 3!
Kids are truly amazing. The best thing is, now you know she has an affinity for letters! What about picking up a LeapPad for her to play with? As far as words, they will come, but a vocab of 50 is awesome for that age.
Just keep loving her for who she is, and she'll continue to blossom. You're doing a great job!