Does it get better?

My wife is a smaller framed woman. Pre-pregnancy she weighed about 118 pounds and is 27 weeks pregnant weighing in at around 138 pounds. I feel so bad because she has awful back pain and keeps saying her stomach just feels so tight. I feel totally helpless and don’t know how I can help other than massages. Just wondering if any other women who weighed around the same had the same issues? We are not even in the third trimester yet and I’m not sure how much bigger she’s going to be able to get given her small frame. Baby boy is measuring at 70th percentile for weight and height and is very strong. His kicks definitely don’t help with the stomach tightness lol. Does anyone have any advice as to how she can help feel less tight around the stomach area? I’m also wondering if women with smaller frames typically tend to go into labor sooner? We obviously don’t want baby boy to come sooner if absolutely necessary. Just looking for some kind of relief for my wife over here.