Babs can knit. She likes to knit. But she doesn't knit the Christmas jumpers - she appliques them. Why?
Well, hand knitting a jumper would make it cost about £200. It would be lovely, but there'd be no money left for the turkey. The only other way to knit a jumper would be by machine. There's a sort of mythical tradition of Christmas jumpers being knitted by grannies. But what we've seen everywhere else is clearly machine knitted.
And Babs cannot stand the flat, characterless effect of machine knitted patterns! That's why she builds up the face with bold pieces of fabric and puts squeakers in and bells on.