Yes Val is the younger sister of Franklin born during the Waid/Wieringo run of teh early 2000's. In the recent Millar run, it turns out that the seemingly normal toddler Val had secretly inherited Reed's genius intellect, but she had been hiding it from the family. Why she looks about 5 or 6 as oppossed to 2 well artists have always failed at drawing kids and drawing a 2 year old doing geniusy stuff does seem a bit challenging.
And Franklin hasn't had his powers since about 2001. He burned them out against this cosmic vilian called Abraxus.