Parents of one of the children told ABC affiliate KATU that the children found Heichel's phone in bushes outside the Troutdale Terrace Apartments Thursday evening. The family says the phone had a screensaver of a picture of Heichel and text messages asking if she was okay.
"I was pretty shocked. I mean I knew right away ... I recognized the face," April Fletcher, the mother of one the girls, told ABC News.
"[The kids] started flipping through some of the text messages ... from [her] uncle, and there was one from Scott that was trying to find out 'where are you. Are you OK?' So I mean it just kind of confirmed it to me that it was her cell phone," she said.
The apartment complex is about four miles away from Heichel's home in Gresham, Ore. Police have not said whether the phone belongs to Heichel.
Read more on ABCNews.com.