Yep, that all sounds very familiar! Definitely the 2-1 transition hun.
There's two ways you can go about it. Either cap the first nap and try for a longer nap in the afternoon, or try and get a longer nap in the morning and AP a CN in the afternoon if you can.
If you'd like to do the first option, I would look at capping that first nap to 30mins max then try for a longer nap earlier than you have been doing because the nap was shorter. I found it really difficult to get the timings right for a longer second nap as DD was prone to UT 45mins naps. I'll post a link about both of them at the end.
What we did was the longer first nap and tried for a CN. You'll have to push out that first A. I think she'll be ok with that as it seems your first nap is quite short hinting at UT. It does take time though. I'd increase by 15mins, hold for 3 days then increase by 15mins again until you get to around midday. Then you just try for a CN around 3.5hrs after waking, if she refuses, fine just do EBT as you have been doing. I found that even the quiet time in the cot for DD helped her get to a reasonable BT. You might have to cap the first nap to 1.5hrs to try and keep a reasonable length of day. The nap should get longer once you increase that first A.
Back in a mo to post the link for you. Let me know which option you think you or your LO might prefer and we'll take it from there x
From 2 to 1 nap transition (10-12m and older)The link within this one about the how, when and bumps I found really helpful too.