How can I help this family....I need ideas on how to handle it.

There is a vendor from one of my fundraising events who told me her husband is suffering from Cancer. I have brought over a meal once in a while and helped with her son's birthday party. Today when I came by to drop something off her house was in shambles, and the atmosphere was very dark and sad. Dishes were toppling out of the sink and all over tables, Garbage was overflowing etc....

I cried when I got back into the car and told my husband I want to clean their house for them, he said he would help. But, how do I offer this service without being offensive? I feel like the family has just given up on life and everything...when I speak to her on the phone she just sounds like she is drained taking care of her husband and 4 year old son.

I don't know how I can offer this without coming off rude?