"I'm so happy with so many friends around right now I am going to burst at the seams with happiness!!!" Hartsock, 28, captioned a photo of herself with McBride and Parr on Instagram Saturday.
"The BEST bridal shower anyone could ask for!! Thanks to all my gorgeous friends for making it so special," Hartsock subseuqently tweeted on Sunday along with a picture featuring all the girls.
In the photo, all the women wore colorful flowers in their hair and appeared to be drinking fruity cocktails. Hartsock dressed in a lacy, white, off-the-shoulder frock.
"Someone's getting married!!!! #DesireesBridalShower," Fedotowsky also tweeted on Sunday.
Hartsock and Siegfried, 28, celebrated their engagement party in Seattle in February.
The couple reportedly committed to having a televised wedding, but against Hartsock's wishes, ABC delayed the ceremony until Fall 2014. Hartsock allegedly had her heart set on a Summer 2013 ceremony but the network pushed for a different date in the hope of getting higher ratings.
"She's very upset about not being able to get married in the summer like she's always dreamed, but she's willing to make the sacrifice because she would marry Chris tomorrow if she could," a source told Life & Style in October of last year.
"She just wants to get married so bad, but still wants to be able to take advantage of having a TV wedding... She thinks it will be a great way to get her enough press to make a name for herself in bridal fashion once everyone sees how great of a designer she is."
Siegfried proposed to Hartsock during The Bachelorette's ninth-season finale, which was filmed in May 2013 and aired three months later. She selected the former professional baseball player over runner-up Drew Kenney after getting over the heartbreak of Brooks Forester unexpectedly dumping her.