Hi Acinonyx..well, playing devils advocate here (and im not being nasty at all, just trying to see things differently)..was the CM really horrible or are you feeling fed up with this yourself (your dd PT and behaviour etc) that CM made you feel worse?
I say this becasue i often take things the wrong way myself if i feel that way out.
However for your cm to keep your dd in pull ups until lunch time isnt helping, she obv is out and about and doesnt want the hassle of clearing up id guess?
There are SO many ways she aand you can encourage your dd to use the toilet and some of which may not work at all, but worth a try...the best method that works for me is star charts!..mindee who is 30 months old is fully TT now, me and mum got together, she told me what she wanted to do, i explained what i could do (taking into account other midnees/school runs etc) and we worked it out..i used a palstic bag under a blanket on pushchair seat to contain any accidents, we went to EVERY toilet we passed 'just to try' where eevr possible and stayed clsoe to mine/toilets for a good few weeks while she was getting sued to it...when ever she told me she needed a wee, she got a star...then she got another for actually doing a wee..when she got x amount she got a treat..mum did same at home and although im sure mum found it harder as i dont have her all week, shes fab..and goes on toilet now with a lovely little pink childs seat that i bought her as an extra special treat for doing a poo on the potty
i def think you need to speak to her and work out why she is being/making you feel browbeaten, she should have you/your childs best interests at heart and if not, then you prob should look around for someone else who is willing to work with you.
oh and i would say EVERY child at some stage turns into a little horror at home time, even my most fantasticly behaved mindees..its a time when they question boundaries, whos in charge if mums here etc and esp bad if you stand chatting, they get restless and cause havoc..ask cm to have you dd ready to go and make sure she writes in her diary what ahs happend each day so you dont need to hang around..if dd gets ready fine for cm, ask cm to get this done for youa s its easier for her as well!..good luck