changing hours

[pingu888]

i have work part time on a job share basis wed pm thur and fri due to i no longer want to work the wed pm and want to work monday daytime instead and have put a request for flexible working and in principle my manager has agreed the only thing is the other person that works part time mon tue and wed is being a bit frosty about it and has given me the impression i am stepping on her toes as its her day in any advice

Is she worried that she is going to be asked to change her hours as it is a job share or maybe that it is changing the role from a job share to two part time roles? Is she worried that clients won't have a point of contact on the days you will be no longer there possibly leading to her being contacted on her non work days? I can see a whole number of these kind of reasons why she might be concerned.
Traditionally with a job share the full time position is fully covered, but with only one person in the office at any one time.

We both work wed pm so just changing the time we are in together