The actress has over 137,000 followers on Twitter and told Metro that they have supported her move into serious drama with Terence Rattigan's Flare Path, which opens tonight at London's Theatre Royal Haymarket.
Smith said: "I call them my Twitter army. My Twitfam. I chat away to them, it's so sweet.
"They're all saying, 'We know Flare Path isn't Legally Blonde but we've been watching war films and we're all coming'. It's amazing because I'm no role model. I like a drink and that."
Of her move into theatre from sitcom Two Pints Of Lager And A Packet Of Crisps, Smith added: "I didn't have any formal training so I always feel like I'm blagging it.
"I hate having to do interviews or go on TV, to the point that I start shaking. I feel like if it's me, I've not got much to say. But when you are acting you are behind so many masks so you feel like a different person."