hmmm, have ot say our experiences wiht BA have not been good, seating wise.
best (worst?) one was 2 years ago, flying to USA - me, dh, d1, then 3 (and ASD), and dd2, about 14 months.
we were flying business, and booked seats in the upstairs cabin, plus bulkhead seat for dd2.
phoned up to sort out meals (always a nightmare - dds are multiple intolerant), and found out that BA had, in their wisdom, reallocated our seats.
Not only that, they had moved dd1 downstairs, by herself. and then tried ot tell me that she couldn't be moved back upstairs, as it was now full, bit that we could moved downstairs with her, but no bulkhead seat for dd2, as that was full...
apparently, since dd1 was booked in as disabled (for extra help at airport in USA while waiting for buggy back form luggage reclaim), that meant she couldn't sit upstairs, regardless of the fact that she isn't physically disabled.
Got her moved back again aftera huge fuss, only ot find they kept re-seating her downstairs.
Ended up having to call them every 3 days or so, for weks before our flight, to keep making sure she was sat with us,even after they removed thedisability tag.
was a real nightmare.