Hello and welcome to the forum. Thank you very much for your question. Has your friend been diagnosed with multiple cysts or polycystic ovaries, called PCOS? Or does she have a singular cyst? Here is information on PCOS https://www.mayoclinic.org/diseases-conditions/pcos/symptoms-causes/syc-20353439 This is a chronic condition and working with her gynecologist will be important. A singular ovarian cyst involves either waiting for the cyst to pass if it is a simple cyst or treatment to remove it if it is more complex. Excessive sweating is a symptom of PCOS. Treating the PCOS can help with these types of side effects. A little more information about her diagnosis would be helpful in guiding you further.
Night sweats can also be a sign of underlying infection and/or cancer.
If symptoms persist, laboratory and/or imaging tests may be warranted.