If you are used to the quality of a full-frame body, I would suggest sticking with one. Perhaps discuss this with your mother and take some council from her experience. I would not go for an APS-C body if I can afford a FF sensor. By not cropping the image, they let your wide angle lenses perform as designed, whereas what you capture with an APS-C crop sensor is like using a focal range 1.6x the value of the lens.
If your mother is willing to let you use her EF glass for a while, get the EF-RF adapter and use it, and in the meantime save up for RF glass specific to your needs.
cheers, TREVOR
The mark of good photographer is not what they hold in their hand, it's what they hold in their head;
"All the variety, all the charm, all the beauty of life is made up of light and shadow", Leo Tolstoy;
"Skill in photography is acquired by practice and not by purchase" Percy W. Harris
