No stranger than it was when "some people" pulled Sabo out of the ocean when he was blown up.
As for her illness, this is a world were every magic power exists. If Law could use the the Op-Op fruit to pull the lead out of his body(which, again, is my current assumption), there are probably other fruits that could have saved her in other ways(a healing fruit, or a lead fruit that just lets the user control the lead to leave her body, etc.)