She has waffled a bit on the number of children - first she planned to have 4, but then abandoned that number as 'too much work', and opted for 2. Lately she is back to four.
She'll casually reference the topic in conversation; shopping in the mall, she has said things like, "Oh, that baby outfit is adorable. Will you buy it for my baby when it's born?", or driving in the car the other day, "Will you come and stay with me to help after my baby is born?"
And most recently, as an addendum to a conversation about birthdays:
Lydia: "When you have a birthday, after I have my babies, they can come to your party and help you celebrate, and have cupcakes."
Me: "Yes, of course, that will be fun. I fully intend to give your children ALL the cupcakes they want!"
Lydia: "Not ALL the cupcakes they want, MOM. They'll have to ask me if they want more than one!"