Has anyone suggested a motive?
The suggested motive was she wanted back with her ex, he didn't, the family (his) were coming to lunch to persuade her to divorce.
How did she both take the leftovers into the hospital/to investigators and also feed them to her kids? Fed it to them after investigation? Why, if you were so concerned about food that you took it for investigating (so it was out of the fridge all that time growing bacteria etc too), would you then feed it to your kids? Bizarre. Police definitely sitting back, watching, thinking give her enough rope and she'll hang herself. She's not coming across well at all.
I guess, playing devils advocate, if she's perhaps intellectually challenged she wouldn't come across well, especially when panicking. We can't all be the sharpest knife in the drawer and some people don't make a lot of sense at the best of times. When they tell a story in ordinary conversation, about something that happened, it can be hard to decipher what went on. I don't mean there's anything wrong with her in a medical sense necessarily, just that perhaps she wasn't at the front of the queue when God was handing out the brains.