It's hard to pin Jessie Cave down to just one genre: even if you gloss over the fact she appeared in Harry Potter as Lavender Brown, she also shines as a writer, comedian and illustrator. Her work is exposed and relatable, dealing in motherhood, dating, and being both vulnerable and annoying in relationships and friendships. Her Fringe show, Sunrise, is about trying to keep up with everything, something her varied career proves she's pretty good at.

How did the transition from acting to comedy happen for you?
I never really considered myself an actress. I would have gone into some form of performance art if I hadn't got Harry Potter. After that, I was suddenly labelled an actress, when that wouldn't have been what I would have said I was going to do with my life. I would have gone into comedy much quicker if I hadn't been put into that pigeonhole. For a long time, I didn't really know what to say when people asked what I do, but now I feel a bit more secure in saying I write and I perform. My shows are an extension of my illustrations, it's all very organic.

How do illustrations fit into your work?
My dream was to be a children's illustrator, and I've always spent every moment when I wasn't acting just drawing. In the last few years, it's become something I would consider part of my livelihood. Getting my book published was a dream come true. The internet has given me this massive lease of life because I'm able to share them and get a response, and that keeps me going. That's actually how I got published, because of the following I got from my drawings online.

Relatability is a big thing in your work: why did you decide nothing was off-limits?
I made it that I was going to do a drawing every day and post it on Twitter; the only reason I did this was because I was trying to get a guy who was rejecting me to notice me. I thought if he saw my doodles which are all about love and stuff, he would fall in love with me. But I didn't realise that all my drawings are really sarcastic and pessimistic, and not really 'fall in love with me' drawings. Now I don't even remember the guy. So, when people share stuff it's the best thing; it shows that unrequited love and rejection are things you want to talk about with your friends.

The underdog mentality is a recurring theme. I am chronically self-deprecating. Even when I know I've done something quite well, I go 'God, I'm disgusting. Don't look at me.' That's kind of my persona on stage: I can't look into the audience's eyes. I feel like I've got to speak as fast as possible and get the hell off the stage.

What can audiences expect from your Edinburgh show?
My last show was after the birth of my first child, which I had after a one-night stand, and it was about the struggles of finding peace in a relationship when I couldn't help but think I trapped him because I got pregnant. That fear of him leaving me in the end because I'm being so neurotic that I actually push him away. Anyway, this show kind of answers that question because, turns out, I did push him away! It's a positive story about a break-up that's for the best and how you deal with the messiness of it all when you have two very young children. It's disgustingly honest, and there are lots of sexual things I've never gone that far onstage with. Almost the whole show is about sex. Just, not in a sexy way.

Jessie Cave: Sunrise, The Stand IV, 3–26 Aug (not 13), 2.25pm, £10.