Hmm ... you're right, Lloyd, there does appear to be conflicting views regarding this matter. And, in the absence of Terpe's expertise, ... ... I'd have been inclined to go along with Michael's 90 days' answer.
According to the following link, however, it would seem there's NO limit to the number of days your wife can spend with her family in the Philippines, so long as she retains your UK address as her MAIN abode when extending her visas up until the stage of applying for Permanent Residence/ILR.
http://1st4immigration-visas.blogspo...ave-to_16.html
N.B. Restrictions on time spent abroad, though, do come into play when a foreign spouse becomes eligible to apply for citizenship.