DEPENDS ON HOW OLD YOU BOTH ARE, IF YOUR BOTH UNDER 18 THEN YES, YOUR MUM HAS EVERY LEGAL RIGHT TO PREVENT YOUR B/F FROM SEEING YOUR BABY UN-SUPERVISED, IF YOU ARE BOTH UNDER SUPERVISION FROM A CHILD SUPPORT/SOCIAL WORKER THEN YOUR B/Fs FAMILY CAN LEGALY REQUEST VISITATION RIGHTS (THIS IS A VERY COMPLICATED COURT/LEGAL SYSTEM WHICH CAN ONLY BE DONE THROUGH A COURT, ITS VERY LENGTHY AND COMPLICATED AND CAN BECOME QUITE EXPENSIVE IF LEGAL AID IS'NT AVAILABLE)
IF YOUR BOTH OVER 18 THEN YOUR MUM HAS NO LEGAL RIGHTS TO PREVENT YOUR B/F FROM SEEING YOUR BABY, IF YOUR BOTH STILL AT HOME SHE COULD HOWEVER MAKE IT DIFFICULT BY APPLYING FOR A RESTRICTION/RESTRAINING ORDER TO PREVENT YOUR B/F FROM COMING TO THE HOUSE, BUT AGAIN ITS A LENGTHY DRAWN OUT COURT PROCEDURE AND THERE HAS TO BE EXTREMELY GOOD GROUNDS TO ISSUE THE ORDER. AT BEST IT COULD JUST CAUSE FRICTION WITH YOU AND YOUR MUM IF YOUR B/F CONTINUES TO VISIT, IF YOU HAVE YOUR OWN PLACE THEN YOUR MUM HAS NO LEGAL GROUNDS AT ALL TO BE PREVENTING YOUR B/F FROM SEEING YOUR CHILD AND AT THE ABSOLUTE EXTREME COULD RESULT IN YOUR MUM BEING CAUTIONED FOR HARRASMENT (IF YOU ACTUALLY WANTED TO FILE A CHARGE FOR IT AGAINST YOUR OWN MUM THAT IS)