I'll agree childhood abuse is one possible interpretation, but like the first foreshadowing flashbacks of Miyuki the images where ambiguous and lacking context. The only definite context we have is Ayako thinking about not understanding her own emotions. Also Ayako's anxiety seems to be manifesting as possessiveness not protectiveness.
Some people have mentioned alexithymia ( https://en.wikipedia.org/wiki/Alexithymia there's your word for the day) associated with autism spectrum, and that could also be part of it (and Asuka too, large genetic component), but there is also another major factor in play.
If I'm remembering correctly, Ayako's parents are dead and and we don't know how it happened or how young she was (before she got married afaics, thus teen or younger)... plenty of scope for sadness, loneliness, pain and fear there (and emotional disassociation).