Teaching kids about giving when money is tight

We're trying to teach our three kids about tithing and giving to others but honestly finances have been stressful this year. Started having them put some of their allowance in a giving jar for church and to donate to families in need. My oldest asked why we give when we need money too and I had to explain that faith means trusting God even when it's hard. Would love to hear how other families handle this without making it feel like punishment.