dzug- if it is a six month allowance I think she will may get away with a six montha absence here rather than a 3 month absence as some of theprevious absences will fall out of the 12 month rolling total.
If she is off May to November she will be okay- e.g. the 12 month rolling total to July will be July 09 , Aug09, May10, June 10 (4 months).
By October 2010 her pre August 2009 absences won't count so her 12 month rolling record will show only May-Oct 2010.
But employers must be wise to people who take 6 months off, six months in, six months off.