Sometimes what is not written can tell us quite a bit.
The mother of Constantine the Great, Helena, is known to have traveled the length and breadth of Eretz Hakodesh, purportedly identifying all sorts of “locations” important to Christians, as well as some based on our traditions. For example, she decided she knew where the site of the eish mitoch hasneh was, and promptly built a church there. etc.
Why do I bring up this delusional old lady and her travels? Because several of the people who were with her wrote down her pronouncements. Primary sources. And though she spent much time in Beit Lechem, where she decided on the site of a pretty famous church, from the sources at the time she says absolutely nothing about kever rochel.
The implication is clear. Her scribes wrote nothing about it because, like the Maaras hamachpela and the mokom hamikdosh, the site was already very well known. She couldn’t apply her “inspiration” to things that were already being identified and used for many many years.