Toilet training and dresses

I have a 3 yr old girl who sucessfully toilet trained a few months ago. She was completely independent with clothing/wiping/washing hands etc. Mom has stated sending her in dresses and tights the last few weeks, and now there have been lots of accidents during the day/peeing on clothes as she's trying to get them pulled down. I asked her last week to put her in pants/shirt for ease of using the bathroom, as she keeps returning in a dress and tights/leggings. Should I just change her into the spare clothes for the day, or do I need to write mom a letter or speak to her directly again? Ideas? Thanks in advance.

I would talk to mum and rather than ask, insist that she not send child in dresses as you have seen a definite increase in accidents as it is harder for the child to toilet herself. Asking implies that the parent has an option when in reality the dresses do not work for daycare and are inappropriate clothing for the reasons you have given and are not acceptable. The other thing you could do is just take the tights off and then toileting should be relatively easy as long as the girl can scoop her whole dress up. That's the other problem with toileting with a dress on when it gets in the potty or toilet.

Tell mom to save the dresses for the weekend. It isn't an option anymore. She is having too much trouble with it. And with her being recently trained, we want to encourage that success, not discourage!