Isn’t grandparenting wonderful? Abbey is lucky to have you near and interested in spending time with her. If she uses correct idioms and tense, she is obviously very bright and has no problem understanding your meaning. So her not answering you probably means either that she is preoccupied or else is trying to establish a degree of control. It’s probably the latter, since you say she doesn’t appear to be “in her own world,” and she’s certainly the right age for wanting to be the boss. You also say she ignores “comments or questions,” but the examples tend to be requests or low-level commands. That makes me think that the non-response is actually resistance.
I think I would try what is sometimes called an orienting signal. Call her name before you make your request, and don’t deliver the request until she turns and looks at you. Do this several times if necessary. If she does not respond, take her chin in your hand gently, turn her head toward you, and verbalize your comment or request. In your additional comments you mention that she also does this sometimes at school, but you don’t mention whether it is a problem at home with her parents. That is critical information. If she acts the same way with her parents, discuss it with them and try to arrange a coordinated approach.
Our parenting advice is given as suggestions only. We recommend you also consult your healthcare provider, and urge you to contact them immediately if your question is urgent or about a medical condition.