She's not too old to learn anything and everything! I have crate trained a 10 year old dog(now 12 and hangs out in his crate at his own discretion!). It wasn't much harder than crate training a puppy! In some ways it was easier as he had better bladder control! Teach her whatever it is you want her to learn in the same way you would a young puppy--gentle, patient and consistent. She'll suprise you with how fast and how much she can learn at 7 years old.