Is 20+ Too Old To Start Ballet?

Hello. I'm from Malaysia. I'm actually 17, but I plan to hopefully take ballet classes when I'm in uni or when I start working. I actually took ballet classes but had to stop because I had hairline fractures in BOTH my legs. But my passion for ballet has only grown. I can't take ballet classes now because,firstly,I'm concentrating on my studies...and therefore have no time to spare for classes... Another reason is my parents can't afford it and think it's ridiculous to do ballet now, at 17. Thirdly, I'm worried about my old injury but a pretty sure it's healed because it happened when I was 9. So, is it alright to start ballet at like 22,23? I plan to juggle uni and a job.