PS. Introducing 2 cats can range from very easy to very hard... the key phrase is slowly. I hope you have an easy introduction stage.

Keep your new kitten in a spare room or your bedroom, with scratching post away from Mitten.

Ignore new kitten when Mitten is around, give Mitten loads of cuddles so she doesn't feel abandoned.

Enjoy your new baby and post trillians of photos as she will grow up so fast.