Rashi needs elucidation.
In pasuk chof Rashi says that Rivkah was “????? ?????” at age 3. The Sifsei Chachomim says that she wasn’t “????? ??????” yet- so she was only “????? ?????”. But in chof-vav Rashi says that Yitzchok waited 10 years until she was 13 to decide that Rivkah was an akara, like Avraham did with Sarah.
The difference is that Sarah was already a gedolah before the 10 year count started. If she gave birth to Yitzchok at 90 and Yishmael was 13 years older than him Sarah was about 77 when hagar conceived which would have been at the end of the 10th year when Sarah gave Hagar to Avraham. If this is true then Sarah started counting at 67.
Rashi himself even says “?? ?????? ?? ??? ???? ??? ?????? ??????” – “until she became 13 and was able to become pregnant”. Meaning before this time she wasn’t able to become pregnant. So what was the 10 years that Yitzchok waited for if during those 10 years Rivkah wasn’t “????? ??????”?
I vaguely remember hearing that Yitzchok waited to consummate the marriage until Rivkah was 12 or something, which would explain some of this but I’m not 100% sure where I heard it from. Or if I even really did.
Besides this, didn’t one of the shoftim or someone have his first child at the age of seven?