If I move away, it might literally kill my mother

Spouse and I are interested in moving to a better climate and lifestyle for our young family. THE only thing stoping me is my mom. I feel so incredibly responsible for her happiness and well being, it’s likely toxic. I see her a few times per month now and she has a great relationship with my very young kids. But she doesn’t help much (not for lack of willingness but 3 toddlers is rough for an older woman)

My mother is a physical able and healthy 68 year old, lives alone, works part time, no health concerns (aside from anxiety/depression). She literally lives to see her family. I have a sister who lives near to her as well, but if I moved to another state she would be extremely heartbroke. I would be the cause of her hour and hours of crying

She is scared of flying so I don’t know how often I would see her