I'm a nanny and in my job I work 30 hours over 3 days. I don't have additional work for the other days as I am quite happy doing 30 hours and like having 4 day weekends 
In September my youngest charge starts nursery and it has been mentioned that the parents may drop the children at school in the mornings so my working day would start at 12. They would still want me to do 30 hours but over 5 days instead.
I've been with this family for 2 years. I really enjoy my job with them - get along well with both parents and have a great bond with the children. However, I don't really want 30 hours over 5 days and less days off - I feel my mornings would just be doing my housework and waiting until it's time to leave for work. Maybe catch a friend for coffee but no long lunches with friends and I lose the ability to have a long weekend away visiting friends or family.
If they did this, is my current job being made redundant? Even though they would still offer 30 working hours per week?