ABC News' Linzie Janis reports:

Instead of celebrating America's freedom this week, a Missouri mother says she is now fighting for her personal liberties after she was ejected from a water park for wearing a string bikini.

Madelyn Sheaffer, 42, says she headed to the Adventure Oasis water park Tuesday in Independence, Mo., with her teenage daughter to cool off and have fun, but was kicked out because of the way she looked in her string bikini.

"You always have the initial embarrassment, but I would say it was followed by indignation," Sheaffer told ABC News.

It was when Sheaffer was swimming in one of the park's pools in her swimwear that she says two park employees told her to put shorts over her bathing suit.

"Why should I have to put on a pair of shorts when I am wearing the same size bikini bottoms as the girls in the pool?" Sheaffer said.

When she refused, a supervisor at the park told her to cover up or leave.

"He said this is a family park [and] it is inappropriate attire, and not only do I want you to put on shorts, but you can put on a shirt too because your [bikini] top is too small as well," she said.

Again, she refused, and police were called to escort her out of the water park.

Sheaffer says she's convinced she was discriminated against because of her age and her fuller figure.

"Just the fact that there were other girls wearing string bikinis - 15, 16, 18 years old - beautiful young bodies, and they are not being told to cover up," Sheaffer said. "I mean, do I have to be 16 and look 100 percent perfect to wear a bikini? Or can I be comfortable in my own skin. Am I allowed to have a matured body?"

Adventure Oasis has not responded to requests for comment, but the city of Independence, which owns the park, told other news media, "The facility made the call and we rely on their judgment."

Sheaffer said she has recently lost about 100 pounds and was happy to be back in a bikini.

"I am very comfortable from where I once was to where I am today," she said.