I would guess not, particularly if there are other guests in F who may not be fans of toddlers in F, much less those without a ticketed seat. You could trade with one of your in laws? Though I'm sure that's not ideal
The woman in 1A was very elderly and was traveling with a companion who was in economy. The woman could barely walk or feed herself and it would have been much more helpful for the companion to sit next to her but that was not allowed so I'm guessing they are quite strict with the rules.