my oldest was like that but my Dr recommended I include him in his lil brothers care n he was great best big brother ever he'd jump out of bed everyday to go kiss his bubba n 5 yes later they're still inseparable

Firm but calm discipline. Give her love and make sure her needs are met, but don't let her dictate how everything goes. There's a balance.

my oldest was the same way and her pediatrician gave me the idea to get her her own baby will dipper bag and the works and when you are taking care of the baby she can hers as well it helped my daughter maybe it will yours also