My sister have white head sore blister on her lower limbs. It appe3ar for few days after that disappear but new one is come, what is it?

Follicultis. Pimples are usually staph albus infection of pores. Probably from shaving, or irritation. Use hibiclens or dial type soap, hold on shaving legs -consider clippers like we do at preop, at hospital. Local warm compress til pimple ruptures with washing, then heals.