I need help! Parents with kids close in age!

I have a 3 year old daughter and a 1 year old daughter. I’m also 38 weeks pregnant with my third and last baby. My 3 year old has shown a little jealousy of our 1 year old but not terrible. Lately though, as we get close to having this baby, she’s been starting to pee her pants again and wants to be held like a baby and really craves all the attention. I give her a ton of attention and make sure I’m really being attentive to her.

How can I deal with this in a constructive way and not get mad?

Im really trying not to get annoyed with her or mad but it’s hard when I know she’s capable of being a big girl.