A Brit mum has become one of only a few in the world to conceive twins three weeks apart after she became pregnant - while pregn

A Brit mum has become one of only a few in the world to conceive twins three weeks apart after she became pregnant - while pregn

A Brit mum has become one of only a few in the world to conceive twins three weeks apart after she became pregnant - while pregnant

A Brit mum has become one of only a few in the world to conceive twins three weeks apart after she became pregnant - while pregnant.

Rebecca Roberts, 39, fell pregnant with her daughter, Rosalie, when she was already carrying her son, Noah.

There have only been a few recorded cases of the phenomenon - called a ''superfetation'' - happening across the world.