How about "Sure we'll help you. Lets go do a grocery together. You need cloths? Lets go shop together."
If they accept, by spending time with you, they will realize that you are not, in fact, the monster described by WT literature. If they do not accept saying that they can't do things with you as you are disfellowshiped, then, say:
"Here I am, with my heart on my hands, willing to help you, and now, not only are you refusing my help, but you are breaking my heart. How am I supposed to feel when you ask me to make sacrifices for you when I am not even worthy of your presence?".
If they say: You can come to our house, but we can't spend time in public. Answer: "If the opinion of other's count for that much, will they feed you? Then, what right do they have to judge you?"
Do not simply give them money without requiring their time and presence, otherwise, all the comments above are valid. They could very well say: "That was the least this sinner could do after everything she has done to us".