UPDATE:

Well yesterday went OK...

It seems my Boss is very keen to get her back on board - which doesn't really suprise me. After they had their little chat I offered to walk her down to the Carpark and basically told her straight to her face what I thought of the situation. She admitted to me that she perhaps could have gone about it in a more straight forward manner. I think she was a little embarrassed about the whole situation and the way it unfolded. Not wanting her to leave on a bad note I basically told her that my problem was not with her - just with the way she handled the situation and said good luck.

When I got back upstairs I went into my Bosses office and basically told him of my concerns...
My Boss told me that IF she does get the job she will only be a Short Term Contractor and that once I come back she will be let go. I told him I am fine with that. I told him my concerns about if her performance is bad at the arranged 3 days per week will this effect my ability to come back 3 days a week and he said no. He said that her performace will not dictate what work hours I will be allowed to come back to. He said that he is happy to work with me on suitable hours when the time comes for me to come back to work. I was really pleased he said that as that was my main concern. I really didn't want him to say "well it didn't work for her so we're not willing to try it for you".

He also told me that if she doesn't hold up her end of the deal then she will be let go and replaced.

I feel more relaxed now about the whole situation....admittedly I was really worried about going on Maternity Leave for fear that she would somehow scheme to repalce me. Now that I know my Boss is on my side I feel better about my decision.

I want to enjoy the birth and staying at home with my Son. I don't want to be worried and waste the precious Mummy bonding time

Thanks again everyone for you help and advice!

xox