We did not eat leftovers growing up for the same reason as your SIL. My parents grew up very poor and both of them were accustomed to living on one meal's leftovers for days. To them eating 'new' food every night was a sign that they had made it up at least one rung on the ladder of success.
To be honest, I don't like leftovers. They never taste anywhere near as good as they did originally and it feels on some level like I'm a pig eating the leftover table slop. I don't even like Thanksgiving leftovers.
My dh, however, loves leftovers. I should note that he is the cook in the family. So we've handled the situation by him taking the leftovers to work for lunch. For Thanksgiving, I will eat one and a maximum of two leftover meals. That is my limit and I will not eat any more.
To be honest, I don't like leftovers. They never taste anywhere near as good as they did originally and it feels on some level like I'm a pig eating the leftover table slop. I don't even like Thanksgiving leftovers.
My dh, however, loves leftovers. I should note that he is the cook in the family. So we've handled the situation by him taking the leftovers to work for lunch. For Thanksgiving, I will eat one and a maximum of two leftover meals. That is my limit and I will not eat any more.