huge hugs Becky,
Both of mine were consistent 45 min nappers till 4 mths, then a switch clicked and they were fine from then on. Oscar even did those wonderful 3 hr naps and 12 hr nights from 12 to 18 mths ish!!! And from 4 mths, 2 x2 hr naps were the norm in this house, I promise.
I think little Martha is very OTd but somehow coping with the nights (my two were the same, as has been for instance ~Emma~'s DD early on and probably lots of others - its one of those spirited signs I think). What happened btw 7,55 and 9,30 before she dropped off? Probably you were trying to sort yourself and DS...I remember those days so well and was so intent on getting that first nap good so as to get myself washed and dressed, DS sorted etc so we could get out the door after the 10am feed....ugh, remember the pressure on that first nap so well.
Anyway, I think the answer is with the first nap - if you can do any APOP to get her off and off for even a 45 min nap but without OTd then the day will probably go better.
Q is , what APOP can you do that she will settle for?
Gripewater on dummy, tight swaddle, radio on between stations and blackout blinds would be my first try....that was my routine at home.
Rocking in the carseat and then plonking carseat in the cot in same dark room, blackouts, radio on btw stations....rinse, repeat if that failed (E was a windy baby though she never really "complained" but would eat the 7am feed so so fast after also very, very good nights that it did upset her tummy till around 12 weeks so the carseat helped with this.
I live in an apartment and so don't have a garden but I would go to our underground carpark (for the dark LOL - we have a nice estate but any light would distract my kids with naptime) with a blanket over the hood of pram and walk shushing till they slept and then bring back to our balcony. This was more something I used for the 11am ish nap with Emma but with OScar from birth as it was only me to get dressed back then (those were the days).
I really think you may have to "ride out" this developmental phase of short naps but I do think you are "entitled to" and should be able to manage one (or even two) longer ones but the OTd from first is causing your day to go asunder from the get-go.
So find her APOP key that suits you if you can - try things that will fit in with being at home for that first nap and that you can do on the rainy days as well...and some of it doesn;t really have to be APOP, just lots of help - swaddle, white noise etc.
And while your DH is still around (is he a teacher off for the summer? did I hear that somewhere?) have him maybe take H out as early as poss so you can get nap no1 sorted....if possible.
Huge hugs and HTH xxx