Indeed, Islam encourages work and urges its followers to help the needy irrespective of their gender, race, faith and age, and also to be positive members of the society. However, one should observe Allah’s limits in his work, especially for a woman. She should be keen on her chastity and honor and keep away from doubtful matters that can violate her chastity.
In addressing this topic, Zienab Mostafa, a prominent Muslim scholar and preacher, stated,
I greatly appreciate this kind of service especially if the intention behind it is to help people and present good image of Islam. However, I advise that caution should be observed and privacy respected. She could continue the same work but admit only females who may be in more need of her help, and thus she would have no problem living with them. If she cannot find females, she can make some renovations in the house to make a separate entry for herself, in order to protect her privacy and enjoy full freedom at all times.
However, her work in general is highly appreciated and is a commemoration of the work of one of the female Companions of the Prophet who had a guest house. So, the work itself is great, but I suggest the previous guidelines in order to protect her freedom and privacy.
May Allah guide us all to whatever pleases Him!