Lauren Maddock, 28, from Westbury, near Shrewsbury, was joined by her cousins and godfather for the first jump, as she aims to raise money for "last hope" alternative treatment in Mexico.
Mum-of-two Lauren is aiming to raise £35,000 after she was given six months to live by doctors. So far £17,800 has been raised in donations.
Her cousin Callum Rogers joined her on the skydive, and he said: "It was an unreal experience. Lauren was just dancing the whole time, she was loving it.
"She enjoyed it so much she went again the next weekend. We were all just on a massive high.
"It's a bit scary when you're free-falling, but when the parachute opens it's amazing."
"She's doing really well. She had a bit of bad news that it has spread to her cheekbones. The fundraising page is up to about £17,000 now, so we've got a bit more to do to get her there.
"But Lauren is in fantastic spirits. She's just taking it day by day."
In November 2019, Lauren, then aged 26 was diagnosed with grade three stage three triple negative breast cancer. She started chemotherapy, but it affected her heart function so had to stop. At this point Lauren underwent four operations, a double mastectomy and had numerous lymph nodes removed. The cancer then returned in surrounding lymph nodes and so she underwent a fifth operation.
Callum added: "It's her last hope. She's been so positive. She's so full of life. It is inspirational, the way that she's handled herself."
Her godfather Martin said: "Lauren is a beautiful, strong and determined young lady who is not willing to give up without a fight. Throughout everything, she has moved mountains for her children, Penny, seven, and Arthur, four, to ensure that they remain the priority whilst making special memories that will last a lifetime."
To support Lauren's fundraising visit justgiving.com/crowdfunding/helplauren21.