Is the wife's request for money from her husband—above the legitimate spousal support (nafaqah shar'iyyah)—considered a forbidden act of begging, regardless of whether she is employed or not?

There is no sin upon the wife if she asks her husband for an increase in the maintenance or for money exceeding the obligatory maintenance, whether she has wealth or earnings or not. This is because such a request does not fall under the type of asking that is forbidden by Islamic law. Indeed, requesting a gift from a friend and the like is permissible. Imam Ahmad facilitated the matter between a child and his father, and its permissibility between spouses is even more appropriate, due to the strength of the relationship between them and the customary ease with which each disposes of the other's wealth.