This is a very difficult question to answer, not simply because it is hard to predict the likely potential scenarios, but because there is a conflict between different values, as we will explain.
Hachnasat orchim[1] is a Rabbinically mandated application of the Torah command to love one’s counterpart.[2] It applies to both poor and rich guests and, in theory, can be accomplished even if the host is reimbursed for expenses (food, telephone calls, etc.), since he is providing a warm, welcoming place to be in.[3] Thus, even if someone can afford to stay in a hotel (and, from the perspective of her needs, perhaps should do that), if she asks to stay at one’s house, or if the situation is such that an invitation is the nice thing to offer, the mitzva is normally a responsibility.
There is a general question regarding the obligation to fulfill a mitzva that comes with a considerable physical or emotional price, and it arises in different contexts. For example, in Living the Halachic Process,[4] we discussed the case of someone who can expect to have a moderate allergic reaction to eating matza on Pesach. The basic assumption is that one does not have to make himself sick in order to fulfill a mitzva. Although it is difficult to do, he must try to determine what normal “price” he should pay in order to fulfill the mitzva. In your case, when it is a matter of your needs and feelings against another person’s needs and feelings, the matter is certainly not easy to determine. You should try to consider this issue in an idealistic but realistic manner. The availability of alternative arrangements is a factor in this context.[5]
There is another element to the complex nature of this question. Just as a host is urged and, to a great extent, commanded to extend himself to make the guest happy and feel welcome,[6] the guest is required to not take advantage or overdo her welcome.[7] If she is causing outright damage, one is not required to continue hosting her.[8] We would certainly say that if she were stealing from her host, presumably even if the host is willing to spend similar amounts of money to feed her, she can be asked to leave. You could make the claim that gezel sheina (deprivation of sleep) would be equivalent. On the other hand, it is difficult to know where to draw the line on such a matter (otherwise, we would all be considered (sleep) thieves at one time or another).
A final, related issue is that if your guest continues to grossly abuse her rights, she is seriously doing wrong. By letting her continue to do so, in some ways you are erroneously facilitating her transgressions. The Rambam[9] says that the mitzva of rebuke, in addition to correcting “religious” sins and those affecting third persons, is also intended for people who are being abused. They should rebuke the abuser (rather than doing nothing and harboring resentment[10]). While one should be very cautious about the use of rebuke, having your guest continue to upset you is unlikely to be in her best interest.
All this being said, we think you should seriously consider the likelihood that your guest was not aware of how her behavior disturbed you. She is less likely to trip the alarm again, and you can probably unplug the phone or mention calmly how its ringing at inappropriate times disturbs you greatly. Hopefully, your friend is a nice person who will be a much improved guest in the future. Thus, if you can put up with her for another night and see how it goes, you would probably be doing a big mitzva, even if you arguably have the right to get out of it. Feel free to follow up as things develop.