Anyone on here know about Stargardts Disease?

My sister has Stargardts, it developed when she was about 5 and she is now 31.
She has just emailed me asking if I can help her find out some info.
She has of late developed round rolling balls of light in her eyes, she’s had them for a while but lately they are more intense. She sees them with her eyes open – she is not completely blind, but legally blind, she still has peripheral vision but no central at all. She also says she is seeing weird things that look like cat whiskers, cats and weird patterns and she sees lots of floaters.
Does anyone know if this sounds like Stargardts or is there something else going on?
She’s booked in to see a professional but the waiting list is 6 months and it’s in NZ they don’t seem to know much about her condition.
She also complains of lots of pressure behind her eyes and sometimes the whole area swells, she’s had sinus scan and brain scan – all clear.
Any ideas?