A. As a stay-at-home mom with no or low income, you can still purchase a life insurance policy, however, your justification should not be "to leave some funds to my kids", instead, you have a strong financial justification - taking care of kids and family at home is an unpaid full time job!
If anything happens to you, your spouse would obviously need to hire someone else to perform the job you have been doing, and that costs money. So, a stay at home mom with no or low income has a right justification to purchase a life insurance policy. As to the specific coverage amount, different insurance companies have different standards, but it's safe to say any reasonable amount would be acceptable from underwriting perspective.