How to cope? Please Help

My step daughter is 10 and her brother is 17. For months now her attitude has gotten worse and worse. She's not listening, hitting her older brother, and just generally acting out.

We've punished her by taking the thing she likes away when she misbehaving and rewarding her when she does well... But still the problem continue. I've tried including her into stuff for the baby but she'll be great one second and total brat the next.

I've been placed on bed rest because of high blood pressure and I'm physical in pain from the swelling getting from point A to B is excruciating for my back hip and legs. I've asked her not to poke me or jump on the bed. I don't mind her rubbing my tummy but everything has a limit.

When she in trouble all of sudden she becomes a leech, has to be all over me or her dad. She comes running in and jumps on the bed, she'll start petting my tummy and after a while I'm uncomfortable so I ask her stop but she just gives me a look 'like what are you going to do about it' and continues or I'm sleeping and she comes to "check" on me and pokes me hard in the stomach.

My husband has talked to her punished her spanked her and nothing seems to get through... (I won't touch her... I may take her toys away or the power cable to the TV but I'm not about to spank a child that's not technically mine)

I told him she's jealous and he should trying spending more time with her because it seems to me that she miss treats me more when he gets on to her or if I've had an exceptional hard day and needed his help.

He trying but he's losing patience and I won't deny mine is gone. I actually flinch every time she comes near me and it breaks my heart. She the only girl and I love dressing her up and doing fun girly things. I did her hair nails the other day and dressed her up when we went out to dinner last night... But I think she needs to see a counselor and get those emotions under some control. Or least an understanding.

I'm started to fear that her jealousy will cause her to act out towards the baby and possibly hurt him because she does not know how far to take things and her father doesn't agree, says she would never. Lets be real though I've seen grown women do dumb things when jealous it's not an easy emotion to deal with.

Am I wrong to suggest therapy? Or there any other ideas or things I can try I'm due in 8 weeks!!