How do mermaids have babies?

Answer 1

None because mermaids aren't real.

Contrary to popular conceptions merfolk do not have tails. They have two legs which they hold together to swim dolphin-style. The only major difference between the merfolk and regular hominids is a large 'tail-fluke' off of each ankle -- which makes the rest of your question very easy to answer.

Answer 2

Mermaids are mythical creatures and do not procreate in the same way as humans or animals. In folklore, they are often said to be immortal or to reproduce through magical means. The specific details of how mermaids have babies vary depending on the culture and story.

Answer 3

There are no real mermaids. So they cannot have babies.