This is how I read your CF's message OP (whilst all the time having a vision of Anne in Motherland running around for Amanda):
you sound really pissed off. - making you sound a bit unreasonable
I just thought we could make do until September = I thought I'd get away with using you until September, does the 'we' mean you and her as this great friendship team (where you do all the helping out)
(to get the funding for y) = link it to something that may or may not actually work out but deflect the ownership of taking the piss from your 'friend' onto the need to wait for fuding (note everyone else has to do the same so it's irrelevant)
with some help from friends and family = surely you are a friend so you'd offer (and continue to offer 'some' help?
but that was so stupid, im doing work and mumming badly. - Interesting use of I (rather than 'we' now), gives you a prompt to say you're not stupid/mumming badly and be a helpful friend by supporting her in her time of feeling so stupid and having a 'mumming badly' crisis because surely as a friend that's what you'd do?
You’ve obviously done way more than you were comfortable with = pretending that you had offered to do something but have now done more than you intended and making you sound a bit unreasonable because it's just more than 'you' were 'comfortable' with rather than her taking the piss
so sorry you feel like - non apology, puts it on you rather than her
I’ve taken the piss. - harsh description of herself so that a good friend likes you feels guilted into saying 'oh no you haven't taken the piss' (and then gets asked to do a 'few' more favours)
I do really appreciate your help. - I'd bloody hope so!!! No points for this statement that was easy to make and also 'gives' you appreciation so that you may feel obligation in return
I know y ruined your day with your sister the teething really didn’t help I suppose!!! - she didn't ruin your day it was y who did that and let's make it a bit jokey with all those exclamation marks!!!
It’s so hard juggling it all and now the childminder said she’s full. - poor me! Any friend is surely going to want to help a friend who is sharing how hard all this is (on top of feeling so stupid and mumming badly)
I’m a twat. I should have taken the space. Now it’s even more of a mess!!!! - more guilt layered on - surely as a friend you're going to need to offer words of comfort to your friend in need and then she'll ask for some help and because you offered words of comfort you will need to follow the logic and help (it's a classic sales/manipulation technique to get people tied into their logic so they end up doing stuff they don't want to do)
I’m going to try and sort childcare and flexible working asap. - really? when? No mention of what she's going to do for childcare in the meanwhile I suspect she's going to need to 'make do with some help from friends and family' because surely any friend would help out whilst she's 'trying' and feeling like a twat/it's so hard/feeling so stupid etc etc
Can I take you to spa? - so that I can create an obligation on you to be a good friend and help whilst I'm 'trying' to sort childcare out. Even offering creates a sense of obligation (again a classic manipulation/sales technique). And a spa really suggests that you're good friends so such a good friend would surely continue to help out a friend who is feeling so awful?
We can have a wine and laugh about how naive I was - feeling 'naive' any good friend is going to have to help her out with how bad she's feeling....