Any fever or infection if only the body is favourable for such things then only get attacks. All mosquito bites will not cause.
Regarding shaking of leg need a examination. Check with her doctor.
Health Tips
Apply ghee over the bite area. repeat 1 hr. once. up to normal skin colour. within 3 or 4 hrs. usually becomes normal. use mosquito net always. Daily 3 times minimum oil application for whole body is must to a baby. Use generous amount of melted ghee in your diet so that milk quality enhances giving good immunity to baby through breast milk. these all prevent any infection. and helps to bone growth too.
for query can consult online.