In the wake of Lex McAllister's death, some of the 31-year-old Bachelor contestant's friends and former co-stars have taken to social media to share their memories and condolences.

"I'm so sad to hear about Alexa. Such a beautiful girl. My heart breaks for her family. Covering them in prayer during this rough time," former Bachelor Jake Pavelka tweeted.

WATCH: 'Bachelor' Contestant Lex McAllister Dead in Apparent Suicide

McAllister appeared on The Bachelor: On the Wings of Love in 2010, which featured Pavelka. She was eliminated after the first week.

Tenley Molzahn, one of McAllister's fellow season 14 contestants, praised McAllister, tweeting, "Remembering Lex. She was vibrant! I didn't know her well, but she was beautiful. Prayers to her family."

Jesse Csincsak, winner of the fourth season of The Bachelorette and a friend of McAllister's, shared a touching post on Instagram, writing, "It saddens me deeply to hear the news of my ‪‎friend Lex McAllister Taking her own life!! You were a beautiful person inside and out!!! You will be missed!! Until we meet again dear R.I.P gone but never forgotten!"

AshLee Frazier, who came in third on season 17 of The Bachelor, shared, "My prayers go out to Lex McAllister's family. You never know what someone is going through. More Love!"

Police received a 911 call on Saturday, saying McAllister apparently overdosed on prescription pills. She was taken to the hospital in stable condition, but died on Tuesday morning when her health took a turn for the worse.

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A source tells ET that McAllister suffered from bipolar disorder. She also hadn't spoken to many people from the show in the past six months and recently became divorced, the source added.

For more on McAllister's life and tragic passing, watch the video below.