It is best that she put your name and address on it, to make it easier to locate you should it be some years before she passes on.
If you are a beneficiary as well as an executor, it can make some matters concerning the administration of the estate more complicated. For example the rule prohibiting trustees of a persons estate for purchasing trust property.
So if you are a beneficiay, it would be best if a second independant executor is also nominated, should you have any problems when the time comes.
If the testator wishes for you to be recompensed for your role as executor then she should state clearly how much out of the estate you are to be paid for this as you will not be able to charge the estate when the time comes.
The Will needs to be dated and signed in the presence of two witnesses. Although the law says that it does matter where it is signed on the document as long as the intentions are clear, it is better that it is done on every page and also at the very end, to avoid anybody contesting it as it not being a valid will.