It's super easy to get singer parts, so there's no issue there. The Pfaff machines can be a bear to work on but are usually all metal so oiling and adjusting will usually do the trick, albeit you may have to re-time. The viking is the major challenge, so it depends on the model. It may have a an electrical circuit board which will requiring many hours of searching and begging it that is the issue. I'd go for it!!!, though I'd give her a Singer back if I had the option. Good Luck.