If the weather is OK, ironbridge is lovely, you can get fish and chips and ice cream, and there's ironbridge gorge festival running at the moment. The Enginuity museum is aimed at children specifically, so worth checking out, theres also Blists Hill museum which usually has some child friendly stuff going on.
Wonderland, the Exotic Zoo, the ice rink and soft play are all right next to the town park, which is really very good.
If you want to drive a little bit, Attingham park has a field of play which is brilliant for kids, as well as loads of space to explore and run around. It's national trust, and has good cafes as well. National trust wise there is also Dudmaston hall.
Telford has a massive indoor softplay called jungle land if you need indoor entertainment. There's also Hoo Zoo and dinosaur world which is very enjoyable for kids who like animals.
Speaking of animals, West Midlands safari park isn't too far away in Kidderminster, and as someone else mentioned there is the Severn valley railway from bridgnorth as well.
I've been to all these places with my kids, they've enjoyed them all. We live not far from where you will be, so know the area well.