The older sister of Gnr Jaysley Beck, the 19-year-old soldier who killed herself after allegedly being sexually assaulted and harassed, has said the army has “blood on its hands” and claimed her sibling would still be alive if the abuse she suffered had been properly investigated.

Speaking to the Guardian, Emilli Beck, 25, said the army had swept Jaysley’s case under the carpet rather than protecting her, and said she would not advise any young woman to join the service.

Emilli described her sister as “fantastic”. She said: “She was everything I aspired to be. She was confident, creative and always her authentic self. She has the most positive outlook on life. I’m older but she was wiser than me. She had a goal, she had prospects, she always knew what she wanted.”

She said it had been hard to speak out but felt she wanted to do so for her sister. “I’ve not accepted that this is my reality and it hurts to talk about it but, if it was on the other foot and it was Jaysley sitting here, she’d do me proud.”

Emilli said her sister would be glad her story was being told. “I think Jaysley would be proud that her struggles have not gone unheard. I think shining a light on her story will hopefully encourage people to speak up.”

Jaysley took her own life after serious errors were made in the way the army investigated an alleged sexual assault on her by Battery Sgt Maj Michael Webber. Webber was dealt with by “a minor administrative action” and wrote Jaysley a letter of apology rather than being reported to the police.

The inquest in Salisbury heard that the way the complaint was handled made her reluctant to report her line manager, Bdr Ryan Mason, when he launched an “onslaught” of “inappropriate messages” against her later that year.

Nicholas Rheinberg, the assistant coroner for Wiltshire and Swindon, strongly criticised “systemic” flaws in the way the army had investigated the alleged sexual assault.

Emilli said: “They cover their own backs, they’ve got their own interests at heart. Jaysley’s complaint against Webber was manipulated as it went up the chain of command to make it sound less severe than the truth, and it makes me feel sick. It took Jaysley a lot of courage to speak up.”

She said the alleged assault should have been reported to the police. “It needed to be handled by the police. That could have ultimately left us with Jaysley still here today. I think for that, they’ve got blood on their hands.”

The inquest heard that Capt James Hook, who organised the exercise that was running when Jaysley was allegedly assaulted, suspected she might have been trying to “generate a situation”.

Emilli said: “He never believed it. He just thought she wanted to get off of the trip. If he had listened to Jaysley, we could have been in a completely different place than we are today.”

Jaysley joined the army after recruiters attended her school in Cumbria. Emilli said: “She just thought: ‘I could definitely do this.’”

Asked what she would say to young women thinking of doing the same as her sister and signing up, Emilli said: “I wouldn’t advise it, going through what we have gone through and learning how these allegations are swept under the carpet.”

Jaysley’s family are calling for an independent body to be set up to investigate claims of sexual offences in the army. Emilli said: “I think people don’t speak up because they think they’re not going to be believed.”

Emilli talked to Jaysley the day before she died in December 2021. “We spoke to her every day, without fail.” When her family didn’t hear from her on 15 December, they knew something was wrong. “We left it a little while because they’d been out partying. We just thought it’s so strange.

“I said to Mum: ‘I’m just going to try and contact some of her friends and see if they’ve heard from her.’ It just didn’t sit right and I was getting more and more worried. And it wasn’t until we contacted her friends that we learned of her passing.”

Emilli criticised the army for appearing to suggest in its own report on Jaysley’s death that “family issues” may have played part. They are a close, happy family. “I think it’s another prime example of the army trying to deflect some of the blame away.”

Emilli recalled a time she visited Jaysley at Larkhill camp in Wiltshire. “We ordered a Wagamama, went for a walk. At any given moment that we possibly could, we did everything together. We truly were best friends and always will be – just because she’s gone that doesn’t change anything.”

• In the UK and Ireland, Samaritans can be contacted on freephone 116 123, or email jo@samaritans.org or jo@samaritans.ie. In the US, you can call or text the National Suicide Prevention Lifeline on 988, chat on 988lifeline.org, or text HOME to 741741 to connect with a crisis counselor. In Australia, the crisis support service Lifeline is 13 11 14. Other international helplines can be found at befrienders.org

• Information and support for anyone affected by rape or sexual abuse issues is available from the following organisations. In the UK, Rape Crisis offers support on 0808 500 2222 in England and Wales, 0808 801 0302 in Scotland, or 0800 0246 991 in Northern Ireland. In the US, Rainn offers support on 800-656-4673. In Australia, support is available at 1800Respect (1800 737 732). Other international helplines can be found at ibiblio.org/rcip/internl.html