Hadrian’s Wall - Birdoswald or Housesteads

That's a tough one, but I'd probably go with Housesteads, as it has a more complete example of a Roman fort there. Plus it is very close to Vindolanda, so I would definitely think you could see both. And there is a wonderful museum there.

That said, Birdoswald is very near Lanercost Priory, which was very interesting to see. Is there any reason you can't visit both areas?

Regardless, I've linked two pages of my personal travel blog below that show the days I went to Housesteads and the day I went to Birdoswald. There are photos there, so you could look through and maybe get a better idea of what is there.

https://mostlytraveled.wordpress.com/2024/04/22/day-34-vindolanda-and-housesteads-roman-fort/
https://mostlytraveled.wordpress.com/2024/04/24/day-35-birdoswald-lanercost-priory-and-hexham-abbey/

I would prioritise Vindolanda over the other two, if possible, as there’s much more to see, a great museum, especially for kids, and a reconstruction of a Roman fort that you can walk about in.

I was impressed with the amount of family friendly interpretative material in the exhibits at Birdoswald, and didn't look at the family printed material, but it is said to be good by those who do have children.
It struck me quite strongly that it was displaying it's history as being a Cumbria Council site until being taken over by English Heritage fairly recently.
As such it used to get a lot of school trips, being just over the Cumbria (now Cumberland) county border, so was set up to appeal both to Children and adults.

If you are studying the wall I think you should visit some of the minor structures, as it wasn't just the great forts but also the milecastles and turrets. Between Birdoswald and Lanercost three good sites to visit are Turret 52a, Pike Hill Signal Tower, and Hare Hill. It may be off the radar but Hare Hill is the highest surviving bit of wall (and for the purists I do know it has been rebuilt).

Bill, when will you be there? Vindolanda has some special exhibits coming up that would be very interesting, imo. They also have meetups with the archeologists and free guided tours. You also might want to check some of the exhibits and interesting events at the Roman Army Museum there. It was really fascinating.

https://www.vindolanda.com/day-planner
https://romanarmymuseum.com/whats-on/

It’s all a bit complicated. We went to Vindolanda last year (very good too) but we’re on the other side of the country and this seemed a reasonable duration deviation from our main journey for this day from Lancashire to Glasgow. These are the two nearest forts to the M6 and realistically I don’t think we’ll have time to see both.

Oh, that makes sense. What a fun thing to do! You might want to check the websites of each as well. I know that Housesteads had a lot of kid-friendly activities and fun exhibits that might interest your 9-year old. https://www.english-heritage.org.uk/visit/places/housesteads-roman-fort-hadrians-wall/things-to-do/ And I also remember seeing lots of kids there the day I went. They have a nice cafe there (I had a plowman's lunch there and really enjoyed it) and the The Twice Brewed Inn is nearby.

I didn't notice as much kid-friendly stuff at Birdoswald, but also wasn't paying that much attention. Plus there were mostly (maybe all?) adults there the day we were there. Honestly, I enjoyed Housesteads more than Birdoswald, but I'm not a 9-year old child. :-)