Sometimes just encouraging fun activites will help build the strength they need more than putting a home workout routine in place. Playing tug of war, climbing up a rope, wheelbarrow racing, etc. to name a few. My kids like to have bridge races. They get into a bridge and walk all around the house that way. It helps with shoulder strength and flexibility. The few times I tried to get them to exercise at home, they were less than enthusiastic and I backed off. If you do get a chin-up bar though..here's a tip. Start with a reverse pull-up. Start in the up position, (put her up there) and have her slowly let herself down. Then put her back up. Do it that way for a few weeks until she can pull herself up. Then gradually increase reps. This is how people who can't do pull ups get the strength needed to do them.