Jessica Simpson's 14-month-old daughter loves being a big sister.

The 32-year-old fashion designer - who is engaged to Eric Johnson - gave birth to their son, Ace Knute, via a scheduled Caesarean section in Los Angeles last month and has been doing everything she can to make sure Maxwell doesn't feel left out.

A source said: ''Maxwell is loving it. Jessica is letting Max participate so she doesn't feel threatened by a new baby in the house.''

Eric is also overjoyed with the new arrival and can't wait until he is old enough to play sports.

The insider added to the US edition of OK! Magazine: ''Eric is so excited and can't wait for Ace to be old enough to toss the football around in the backyard. Jessica swears she can already tell what kind of personality he's going to have and it's daddy's boy all the way.

''Ace already has more toys that he will ever need. Toy cars and trucks, fuzzy footballs, basketballs and a little basketball hoop.''