They're not Masrur's kids, he was just taking care of the Fanalis corps. Those kids have no parents in that side since they came from the great rift.
It's in the manga itself lol. The moment Alibaba thought they were Masrur's kids, Masrur replied that he became the captain of the Fanalis corps, so they're taking care of them. It's just like how the other Fanalis calls Mu "brother" when he was still the captain.
And besides, there's no way Masrur will have kids those age in just like 3 years passed, exactly 2 years passed when he left Sinbad.
For Sharkkan and Yamraiha, dunno... no information given about them.
What about Yamuraiha and Sharrkan did they get married??