I can't help with the legs because DD is the same, however I agree with kellz that she might be ready to drop one of the day naps? My DD did at around five months, now she has a morning nap at about 9am or 10am, and an afternoon one at about 2pm, night time (all going well) is 7pm - 7am.

I found this age tough because they seem to have more energy but can't burn it because they're not crawling yet. Maybe a jolly jumper would help wear her out, it will probably encourage the jimmy legs more though!