Scare her by telling her your only giving her exactly what she gave you and your husband for your wedding, then after she grovels give her what money you can afford
NTA. Your sister and her partner should have been saving before this time. Give what you can, or want to. Also, can't blame your husband about not wanting to give anything.
In a situation like this where money is involved, give what you can afford and nothing more.
Scare her by telling her your only giving her exactly what she gave you and your husband for your wedding, then after she grovels give her what money you can afford
NTA. Your sister and her partner should have been saving before this time. Give what you can, or want to. Also, can't blame your husband about not wanting to give anything.