Hi - great to see you!
So sorry for Jenna's issues. She is not too young for this. Many dogs get "juvenile cataracts" for no reason at all except genetics - my Wylie's started when he was around 4 or 5. He is now pretty much totally blind (he's 12), but has our house memorized quite well.
If there are cataracts, you must give Flurbiprofen drops -- as these drops are the prevention for the cataracts developing to glaucoma. If glaucoma develops, you may have to remove the eye entirely.
If the cataracts are candidates for surgery, that usually runs about $3500-$5000+, btw.
Keep us posted and best of luck!