My younger sister is delayed and I get stressed everyday about it.

Firstly I wanna apologize because this is a parenting sub Reddit and this isn't exactly parenting but I thought this was the best option.My younger sister has a development delay with her reading. She takes medication to help her focus but, has serious trouble reading and remembering things in math and science. She is in grade 5 and reading at a grade 2 ish level. She works extremely hard and ahead of where her TA's thought she would be. Anyways, I am her 19 year old brother, and it bothers me everyday when I see her that she will be bullied/ not have a "normal high school experience." Right now they have estimated her to graduate high school at 22. With enough work or maturity, do they ever catch up? Shes done great so far and I wanna believe with enough work at this rate she can do it. Is this false hope and I just need to accept it? And how can I stop worrying and be more helpful?Appreciate any comments, Thanks via /r/Parenting https://ift.tt/2JhZ5Iy