CAT LOVERS - I have a question!

I've had my cat for 2-3 years. She's never really been the playful type and never really liked a lot of attention, she mainly either slept, ate or wanted to be outside. About 3 months ago, she had her second litter of kittens. They went to their new homes at 8-9 weeks.

For the past 2 weeks or so, my cat has been VERY playful. She's running around the house, chasing things, attacking our legs (in a playful way) and I'm not really sure why.. as I said, she's never been playful. She wasn't like this with her first litter after they went to their new homes either..

So, anyone know why she's all of a sudden so playful? Lol, it makes me a little nervous since my little boy is due in 2 months.

Also, here's a pic of my kitty, sleeping with a water bottle.🤣