They look great! So maybe theyre a bit more pale but yes the light made it seem like it was way more than it really is. The yellowing is okay as long as its happening from bottom to top without affecting the upper leaves, in a SCROG the light doesnt reach much further than the upper canopy so as I told you they tend to yellow a lot more than if grown without any technique but its still a natural process. The plant doesnt want the leaf anymore, its old and barely getting any light, starts to take nutes and slowly detaches it from the stem until it falls on its own or stays there dry (its good to remove the ones that are already very yellow or dry to avoid mold, if theyre only slightly yellow you can wait a couple of days til the plant is done taking most of the nutes, easier to pick them up too). I never had a mother cause I have never worked with clones or tried to polinate it with a male, but I assume you wanna keep the nitrogen high always since its permanently in veg mode but even then sooner or later some leaves are gonna be discarded by the plant as it gets older and grows new leaves.
EDIT: Forgot to mention, in late flower is okay if the upper canopy is yelllowing, the plant is making a final effort of getting polinated and might take nutes from all the fan leaves. Specially if you flush it, but is okay. Im pretty sure you have seen plenty of pictures of mature weed with yellow fan leaves, or even purple or copper which is the combination of yellow, green plus blue from that strain or the cold.
Oh and another thing, even green leaves might come off easily, sometimes they dont even have time to yellow before becoming useless and they dont even try to take light, they just hang from the stem, those I remove too. Sometimes it can be that they are thirsty or too wet, then that happens too, but if you know its not thirsty or too wet those leaves will come off easily.
