I myself think you can and should see it as Animal Assisted Therapy, sort of. After you gave your everything into this little one whose fate it wasnt to live, the aliving and healthy ones gives now to you their support, reminding you they are giving you love - and them need love. In short, the mom is doing her earnest to help you recharge your batteryies.I still have to constantly be by the mom. How long do you reckon she will be this clingy?
I know quite a few moms ARE clingy of their owner / caretaker. But I also know for sure cats DO feel if their owner is sad and grieving, and very often they do their outmost to help their beloved owner / caretaker. They do so with their cat friends, they do so for their humans they care about.
So these arent my quasi-religious speculations, its a biological fact.