From what I can gather from her SM she absolutely adores her son, he appears to be her whole world. He looks extremely well looked after and loved.
Just my own opinions as follows...
He was found in just a t-shirt and nappy, no shorts, socks or shoes. If you're driving to a family members or friends you might pop your child in the car like that but not for a 10-12 hour drive. The only reasons I can think he would be undressed in such a way is if maybe she was changing his nappy in the truck, something happened to her and he wondered off. Or she and Kam were in a motel/apartment (I'm going to guess under bad circumstances) and Kam managed to get out and wonder off.
I believe something terrible has happened to LC, what I couldn't guess at, but from all the evidence gathered so far she would not willingly have abandoned her little boy. I can see she has made some bad decisions in the past but that does not make her a bad person or even a bad parent. I have a few thoughts as to why she might have been in FL (again going from the evidence posted) but it is all just speculation.
I truly hope for a happy outcome in this situation but I'm a realist and I think Kam is going to grow up without his Mum.