I am a huge sucker when it comes to heartwarming shenanigans like this but. BUT. If Lady Jelly procreates in the future, what will her children be?
Aside from that, the fact that the elder Slime's partially parted head has a backstory really shows how detail-oriented this is. I love it so much.
Logically, they should be human. Her blood has been replaced with slime but otherwise her body is human. Her children will be fully human with half their DNA coming from the original Jelly and half coming from the father.
The author could probably come up with a few reasons that the children wouldn't be fully human, but unless we are given those reasons, we can't assume that it'll be the case.
However, there is the horrifying thought that Jelly will kill her human offspring soon after birth and have her mini-slimes inhabit the body, having a child that is both her human offspring and slime offspring. The idea makes me a little sick, actually.
I'm sure she would never, but the setting allows for the possibility. There could be slimes slowly taking over human society, one body at a time.