ive had lymphoedema for years and haven't had any problem with leaking through the skin. I do wear sleeve most of the time as whenever I bend my arm the elastic sleeve pushes the lympth fluid up the arm so it can drain away. this stops the arm from swelling
ive had cellulitis in the arm, which can be a problem if you have lymphedema. This is when a scratch can cause infection, you notice it when you can see red spider veins under the skin, and they spread up the arm over a few hours. If this happens then I have to have a course of antibiotics as soon as possible.
Any signs of this, she should go to the doctors, and keep nagging about the sleeve