As Robbie said, Dr Sharman could well be right, but as a scientist she should know better than to say “aliens exist, there’s no two ways about it”. It might be more likely than not that other lifeforms exist somewhere. It might be almost definite. But there’s definitely more than one way about it, unless she has evidence she's not sharing.
As to aliens being here, I wonder if she has a more developed view than what comes across to me as “anything is possible”? For instance, how they might have got here?
I took the suggestion that bad people are aliens as a joke and don't have a problem with people indicating they aren't serious by use of emojis or 'lol'. It's hard to signal in writing that you're not serious otherwise.
I sometimes hope to be beamed up and taken back to my civilised and peaceful home world, especially after exposure to a R4 Today vox pop, but sadly it's a fantasy.