It's a fairly scary article but parents of spina bifida kids need to know what they might expect so that they can deal with it early enough that it is less of a problem as the kid grows up.
A fellow RN at my last job had spina bifida, so the mildest forms need not impede a child through life. However, damage at lumbar and/or sacral nerve roots means the kid will be a late walker and that potty training will be very problematic. Some kids have benefited from surgery to replace bowel and bladder openings with pump operated devices, but such surgery has to wait until the child is older.
Until then, it's incontinence briefs, I'm afraid. She's not resisting potty training at this point. She simply might not be capable of it no matter how much she wants to be.