Tears streamed down a 4-year-old's face as she rushed out of MacDonald's bathroom. Her mother saw something on her daughter's leg that made the whole ordeal even worse.

It's always important to allow your kids to do certain things for themselves to help them grow and become independent. But sometimes, it can be hard to let them out of your sight.

Kaya Langmead was visiting McDonald's restaurant over lunchtime with her mother, Nicole Langmead.

And when the 4-year-old girl asked her mother to let her go to the restroom on her own, she said yes.

Believing Kaya was 'old enough' to go to the bathroom all by herself, Ms. Langmead decided to wait outside the restroom.

But before Kaya entered, the mother saw two teenage girls leaving the restroom laughing.

She didn't reflect on why the two girls were laughing. However, when her daughter returned from the bathroom in agony, she suspected something wasn't right.

Ms. Langmead explained the incidence:

"I was waiting outside the toilets with my two daughters for quite a long time."

"We were just about to give up when these two girls came out of the bathroom, laughing."

"They were probably in their early teens. I didn't think too much of it and Kaya went into the toilet."

"A short while later she came out in tears and told me that she had become stuck to the seat."

After reviewing the CCTV footage, the police describe the girls to be between 16 and 18 years.

One had long blonde hair, wearing a red and white check shirt and skinny blue jeans. The other had shoulder-length brown hair and an Adidas tracksuit.

Langmead described her daughter's ordeal:

"She said something had hurt her bum, but it never crossed my mind it would be glue."

"I thought maybe the seat had moved or something, but when we checked it over, there was glue everywhere."

"I was completely shocked, and I then checked Kaya over to see how badly she had been marked."

"She was left in tears, and the skin was ripped off the back of her legs."

Following the horrible incident, Ms. Langmead shared it on Facebook, warning other parents to prevent this kind of horror from happening to their children too.

She wrote:

"To the two young blonde girls that thought it would be so hilarious to put super glue on the disabled and baby changing toilet in McDonald's, I just want you to know that I am still having to console my four-year-old daughter who was unfortunate enough to use the toilet after your little prank."

"I hope you're proud of yourselves. Your families must be so proud."