Having a lay-in.

It means, to lay in bed.
Not necessarily sleeping, enjoying peace and quiet alone.
Whilst the husband gets up, sorts out dotty
Changes Flo's nappy.
Makes Louie and Olivia's breakfast.
And makes Heidi a cup of tea in bed.
Whilst he's keeping noise to a minimum watching motd.

Where's Heidi?

She's having a lay-in.
She'll be there until one of the kids screams or the dog jumps up and licks her face.