Active, apostolic sisters who work for and in the community are usually given a stipend for necessities, transportation, if needed i.e. car, bus fare or whatever. They are not accepted if they have dependents. If a family crisis occurs they can ask for a leave of absence if professed and sometimes before profession.
Most sisters that do not wear a habit are quite adapt with The Salvation Army, Goodwill, yard sales and other chartable outlets. They usually look quiet “smart” without looking “rich,” but modest and appropriate.
Poverty starts in the heart and soul, not in how you look and what you wear. Jesus went to his death in a very fine garment that His mother made for Him and the soldiers gambled for. I am sure He wore the robe to please His mother and not to please Himself.
As for giving the sister a new coat and shoes, why not give her a gift certificate to a good store and just send it to her in the mail. That way she could pick out what she needs or wants and she wouldn’t know who sent her the card. I am sure that she would be pleased. Cloistered sisters have their needs provided according to the rule of the community. However, they could always use financial support as they are dwindling due to age, vocations and income.
Just another thought: the little sister may be very happy and content just as she is.