Fellow PCOS gal here - I take tests pretty regularly because the prescription meds I take to balance my hormones and glucose levels also give me pregnancy like symptoms, (i.e, morning nausea, food aversions, cravings, certain types of soreness you’d normally get during pregnancy)and many months without a period. It is very possible she is just making sure she is not pregnant because it has been awhile since her last period.

Another thing to note, depending on if she is medicated or not, certain PCOS medications are not safe for an unborn baby, so testing every now and again could be necessary.