Jealousy problems

💖Jenna💖 • Proud mommy to two sweet babies 💟B 11/1/16💟💙E 11/8/17💙 Married to my sweetie 3/20/16💘👨‍👩‍👧‍👦💑💘

My little one is not too happy with her little brother (7months) being around and he's crawling now and playing a lot but lately big sister (19 months) is hitting him in the head with toys, smacking him, pushing him down, etc. And she leaves bruises sommetimes. Just wondering if anyone else has had this problem and how you handle it? I'm scared to even let him on the ground to playI anymore.