Hannah, who starred onThe Bachelorette's fifteenth season earlier this year and eliminated Peter in third place, toldEntertainment Tonight that Peter should ask his final bachelorettes some tough questions, especially in the Fantasy Suites when the cameras were away.
(While it won't premiere on ABC until January, Peter's edition of The Bachelor finished filming earlier this month.)
"God, that's really hard for me to give [advice]. I think it's just taking those moments to really get to know the person without the cameras and to make sure that you're really vulnerable and honest with each other," Hannah told ET.
"Just because the show has ended, you're life is still starting, and [so] really get to know what you're in and be able to make confident decisions for yourself moving forward to."
At the end of Hannah's season, she got engaged to Nashville-based musician Jed Wyatt, only to break up with him five weeks later because Jed had lied to her about his dating history.
Jed initially told Hannah that his romance with ex Haley Stevens ended one week before taping commenced, but Haley told People in June that Jed traveled to California to film the show in March still dating her.
In addition, Haley alleged in her interview Jed had said he was only going on the show to boost his music career and they'd resume their relationship once he returned home.
"Just because the show ends, it doesn't mean that's the end," Hannah explained.
"And you really need to understand what your relationship is, and I hope that his is a fairy-tale and something he's always been looking for."
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The first promo of Peter's season has already been released and shows the airline pilot posing with a red rose in front of a windmill, which is a nod to how Hannah said she and Peter had sex four times in a windmill on their Fantasy Suite date.
When asked to comment on the windmill promo, Hannah was at a loss for words and just burst into laughter.
"I'll always be asked about my journey and my men," Hannah said with a laugh. "I guess I just -- I don't know! That was a memorable moment, I think, for everyone -- so they put it in the promo!"
While Peter has been filming The Bachelor, Hannah has been competing on Season 28 of Dancing with the Stars with her professional partner Alan Bersten.
Hannah and Alan will dance in the hope of winning the mirrorball trophy in the finals next week.
In terms of how they'll attack the finals, Alan said he's "really excited" for their freestyle, and Hannah noted the highly-anticipated dance will be "a continuation" and "celebration" of herself.
"I want it!" Hannah said of winning the competition. "And I'm appreciative of everybody keeping me in."
Hannah and Alan never finished in the bottom-two couples during their Dancing with the Stars experience based on home viewer votes, so it's apparent the pair really has a shot at victory.