Broody mama chicken pecking babies! Should I give her another chance?

[Vegan Mountain Mama]

Hi, my broody bantam Nellie is usually such a gentle, patient and competent mother...she successfully raised a chick that wasn’t hers last spring. She showed broody signs again this spring so last weekend I got her a bantam chick and slipped it under her and she took right to it. Sadly a couple days later a rat killed the chick. Nellie seemed very confused about what happened and was still sitting on the nest diligently and calling for the chick (making the little chirpy noises to call baby to come eat)...very heartbreaking!
so naturally I thought it was important to get her another chick as soon as possible to fill the void (she also tends to he y very depressed anyways when she’s broody and has no chick). So I got her a new chick but she wasn’t quite as welcoming...she chirps to call it to eat and she lets it sit under her, but this chick has been somewhat weak and doesn’t really answer to her cues (like when she calls it to eat) and it’s not a natural eater, also a bit sedentary. And when it just sits there by the food near her, that’s when she pecks it (she hasn’t actually done any damage, I wouldn’t allow it) but I’m concerned and confused. I ended up getting a heat lamp and another chick in case she doesn’t get better...the 2nd chick seemed to soften the mama a bit and her pecking at either of them subsided. But now she’s doing it again to both of them (not hard enough to do any damage but it’s making me nervous). I’m worried she was very attached to the chick that got killed and now she’s resentful of these ones, but idk if I’m reading too much into it...
....what do you think this mixed maternal/irritated behavior is about? And should I be patient with her and let her continue to be with them while I monitor and protect the chick myself?

 

[pennyJo1960]

Keep a quiet eye on them no doubt but sounds as if she may toke them both

 

[aart]

but idk if I’m reading too much into it...

I believe you may be.
The chick dying then another appearing may have her confused,
the interruption in brooding could have thrown her off.
How long between chicks death an intro of new chick?
Hard to say what's going on exactly.
The pecking can be fine, best not to interfere, it's how chickens communicate.

 

[centrarchid]

Hen and chick(s) need to be at complementary stages in breeding cycle to bond. That not realized in this situation. Even my best broodies that have raised 70+ chicks will not take chicks outside normal parts of broody cycle, even when said hens are broody. Failure to take broody cycle into consideration makes predictions on success very poor.