Neighboring civilizations were in contact in antiquity. Just as through hikers on the Appalachian Trail today can walk 2,000 miles in a season, people could back then as well. With horses, camels and sailboats; it was even easier and quicker.
Royalty always faced the problem of finding the best marriage partners for their kids, and the economic and military advantages of joining with another kingdom are always strong.
Ancient Ethiopia and Yemen (and Israel) are close together physically. A days sail (more a matter of hours really, with slaves rowing). It would be common for them trade and visit regularly. Occaisional intermarriage and competing personal interests would probably draw them together and push them apart many times through history.
That's merely some just-so speculation. Hatshepsut's bas relief showing and describing the details of her trip to Punt portray and name the port official who received her and her delegation, and his son is mentioned in the OT as having the same job later on. The attempt to put Punt in Yemen and to put Sheba in Yemen (at a disjointed, later time) is just a kludge, nothing more.
Thats a stretch
There was no Suez and even then its about 1000 nautical from Elat to Yemen closest port and Elat itself was a trek across badass desert from Jerusalem
Ethiopia ditto
Syria and kingdoms to the north and Egypt were much closer
Sheba is popular today cause she was a chick and dark....Hamitic I think..who knows
Solomons mommy was hotter
For inspiration Ruth and Esther are mo betta
How fast could slaves row those unwieldy vessels
I profess ignoramoose ness