"She wasted the time of so many people who could have been helping real families in need," she said.
When she realized she had been exposed, Beushausen quickly took down the blog, and apparently tried to erase her digital identity from Facebook, MySpace and Twitter.
Calls to Beushausen and her parents initially were not returned to ABCNews.com. But later, she sent the written apology to ABC News as "Good Morning America" prepared to cover the story.
In it, she claimed that though her account of Baby April was a lie, she made another claim of thwarted motherhood -- that she was "no stranger to losing a baby."
"The pain is very constant," she wrote. "Is what I have explained above and the other pains that are unseen and only in my heart an excuse for all of this? -- No. Absoltely [sic] not. But I will be the first to say I don't even understand all of my actions."
Beushausen also admitted to the deception and apologized for the hoax in an interview Friday with the Chicago Tribune.
"I know what I did was wrong," she told the Tribune. "I've been getting hate mail. I'm sorry because people were so emotionally involved."
"I've always liked writing. It was addictive to find out I had a voice that people wanted to hear," Beushausen said. "Soon, I was getting 100,000 hits a week, and it just got out of hand."
"I didn't know how to stop," she added. "One lie led to another."
That apology is little solace to thousands of bloggers who followed her posts nightly, sending in prayers and mailing gifts.
"I'm still feeling a lot of hate towards her," said Jacki Gallagher, a 30-year-old blogger from British Columbia who followed the site from early on.
"Reading her site was part of my life. I hand make toys and was ready to send something, because she had moved me so much. She wrote beautifully and that was really the seller. She didn't just make short posts, she put a lot of time an effort into this," Gallagher said.
Beushausen told the Tribune that she did not make much money from the site and that she encouraged people to make donations to an Illinois ministry and pregnancy clinic called PASS.
"We never had any direct contact with this woman and we are investigating," said Rick Ligthart, executive director of PASS. "We know of one, at least, donation related to this hoax and we want to make sure we do the right thing.
"This lie is another indication of the brokenness this country's moral fabric," he said.
The one known donation received by PASS came from Ryan and Raechel Myers. Raechel Myers and Beushausen attended college together and the couple printed and sold T-shirts to raise funds.
The couple also reportedly donated at least $300 to Beushausen.
Making the deception all the more painful, the couple reportedly lost a child to the same illness Beushuasen claimed April had.
"She robbed the story from her friends. It's just sick," said Russell Myers.
In her written apology, Beushausen denied receiving significant cash donations.
"I received a limited number of gifts through my P.O. box. A baby hat, a pair of little shoes, a hair bow, a crocheted blanket, etc," she wrote. "I never once received a check or cash in the mail. Ever. (I have not been to my P.O. box in a few weeks and will not be going back. I assume any sitting mail will be returned to sender).