The best decision my DD made (as a 13 year old) was to repeat algebra as a high school freshman. She’d received an A in it in 8th grade, but just didn’t think she knew it. She took Honor level as a freshman, and that put her behind all her peers, but she really learned it. She never took calc in high school. She was petrified going into calc I as many of her classmates had taken AP calc. She studied until she could study no more, but many classmates who’d had calc treated it like a review and didn’t get an A. Calc II was harder and she got off to a bad start, but called me today to say she’s sure she did well on the final.
I think it is better to go slow and steady, making sure you have one level down before moving to the next.