Yup, my wee sow is the same
From around 6 weeks the piglets get less and less access to the 'milk bar', she sometimes lies on her belly to prevent access but other times we've seen her send them flying with a toss of her snout
It's completely understandable - especially with a bigger litter (I know what I'm like with the kids
) Providing they're all doing well on solids I wouldn't worry. Only thing I would say though is to have them completely seperate to her for at least a couple of days before they go off to their new homes, that way you can check that they are actually completely weaned and coping with it.
Karen