I found an answer to the bnosov question. Its the sifsei chachomim on that above pasuk ‘ubnos banov’ on the rashi who says they were serach bas asher and yocheved bas levi. Its beautiful but too long to write out so ayin sham.
Coffee pls bring mekor for your assertion that only the sons descendants were counted despite many pesukim seemingly to the contrary eg kol nefesh lebeis yakov habah mitzraima shivim (ber 46 27) or kol nefesh yotzei yerech yakov shivim nefesh (shemos 1 5) or beshivim nefesh yardu avosecha mitzraima (dev 10 22)?
Ps Look in the Or Hachaim (46 7) on why the shibud began before yocheved and serach were niftar when it should have waited till that whole dor died!