Louis Tomlinson became a father figure to his sister Lottie Tomlinson in the wake of their beloved mom's death.

The mom-of-two was 18 when Johannah Deakin died from leukaemia at the age of 43 in 2016, three years before the siblings lost their sister, Félicité Tomlinson, following her accidental overdose involving anti-anxiety medication, cocaine and painkillers at the age of 18.

Lottie, 28, admitted it has been difficult raising her and fiancé Lewis Burton's son Lucky, four, and daughter Flossie, 22 months, without Johannah, praising singer Louis, 34, for stepping up and supporting her following the family tragedy.

Speaking on her brother's 29-year-old girlfriend Zara McDermott's Feel Good Formula podcast, Lottie said: "It's really hard having your own kids without your mom. Not gonna get upset. Literally said to myself, 'Don't cry.'

"But yeah, I think my sisters have been a big one, we've all sort of come together and tried to look after each other and it makes me feel closer to her in a way because obviously I know how much being a mom meant to her.

"And it means so much to us, I think, because of how she brought us up with being so maternal and I think that's why we all are how we are because of her but yeah, it's hard."

Lottie admitted she often puts her own feelings last while trying to stay strong amid her ongoing grief.

The model explained: "You're sort of bottom of the pile. That's how it sort of feels, I think that's why I just broke down then, because I'm trying my best just to be strong, hold it together all the time.

"And then when someone actually says it, I'm like, 'Actually, it is really hard.' And, like, because I'm so grateful for the life I've got and that's what sort of got me through everything, is having that mindset.

"I think you then sort of don't let yourself sometimes even feel sorry for yourself in that way, and then obviously in them moments because I've held it all in, I've then fallen apart.

"I think that was a big thing when I was grieving, that I would feel so guilty if I had a day where I felt happy and OK, and then when I was feeling really low, I'd then look back and just wish I'd embraced that one day where I felt OK."

Lottie reflected on the importance of being kinder to herself while grieving Johannah.

She continued: "So looking back, it would've been nice for me to be more gentler in them times, and just, ride the waves. That's the thing.

"You've just gotta ride the wave and try and make the best of it and embrace everything. She was just such a dedicated mom.

"She was just such a full-time mom to all these kids. Don't forget how many. I mean of course, doing it with two is hard. I'm like trying to think, can I manage a third? She had seven.

"So yeah, I don't know how she did it, but she was just such a full-time mom, so I think that stuff did take a backseat for her."

Lottie was 15 when Johannah put her on a flight to New York to join One Direction on tour and gain work experience from their hairstylist Lou Teasdale, now 43, where Louis "stepped into a fatherly role".

She added: "I appreciate now that he even let me come on the tour. But I think it was probably more my mom, where he was like, 'I can't say no to my mom.'

"But it was actually really nice in the end because he sort of stepped into a real fatherly role on that tour, and he didn't let me get away with anything.

"Like, if I put a foot wrong, he would tell me, and I appreciate that now, maybe not at the time but he basically brought me up over those few years 'cause he was the only family I had with me.

"I think it gave us a really strong bond that you sort of can't explain because we went through that together."

Lottie and Louis leaned on each other even more following the deaths of Johannah and Félicité.

She said: "We're so close now, and I think it is because of those few years. Me being there with him, I think in the end he liked having me there for the support.

"And he was sort of fathering me a bit, but I was almost mothering him a bit as well. So I would pull him up on stuff if he was acting a certain way and it sort of worked both ways, which was nice."