I understand that your friend might be eager to start on hormones but taking someone else's meds really isn't a sound option for a couple of reasons. When someone starts hormones they need the support of their medical provider to make sure that they're not exposed to additional risks and get them on the best treatment for them. The dosage needs to be calibrated to make sure it's suitable for her and that the way she is taking the medication is appropriate for her lifestyle and needs. Another important fact when we're talking about HRT medication for menopause is that it tends to use different hormones to those used for transgirls and women. Risking taking the wrong drugs at the wrong dosage isn't a sound option.
So, what if we talk about other ways we can support your friend in her transition? For example, does she need advice and support on accessing healthcare? Is she looking for ways to express her gender identity until she can start this kind of treatment? These are all things we can talk to her (or you) about to make that wait for hormones a little more bearable.
(I also want to add that if and when you use someone else's prescription, that person won't be able to get access, or all the access they need, to their own medication for their own health issues that medication is for, which is -- hopefully -- obviously super not cool.)
Never doubt that a small group of thoughtful, committed citizens can change the world. Indeed, it is the only thing that ever has. - Margaret Mead