If your husband gives you pocket money to keep for you or spend as you want, then this means that the money is yours. Such money owned by you is your responsibility and any remaining amount of it must be applied for Khums.

If your husband gives you the money to keep it for home expenses to be made on his behalf, then such money is still his money but kept with you. In such case, no Khums on you because your husband is still the owner of that amount.

Wassalam.