Hi Mary,
As an add on or nuance to her existing qualifications, I see no harm in it. However, there is no relationship between the online Msc in Positive Psychology and the actual clinical psychology training required to work in psychology per se. It would not be recognised for consideration for clinical psychology training. Check with PSI, Psychological Society of Ireland, for clarification. If your friend is already working in child psychotherapy, it may be of use.
I am with dub_nerd with relation to 'Life Coaching'!