I think I finally discovered how Old Yelena currently is. So in Black widow Yelena was 6 and Nat was 11 meaning they’re 5 years apart. According to google Nat died when she was 39, meaning Yelena would’ve been 34. But Yelena was also in the blip meaning she’s actually 29, and it’s currently 2024 in MCU universe so 2024-34= 1990. Yelena was Born in 1990!!!!
Sorry this stupid thing has been stuck in my brain.