OP, to be fair from what you've written alone, I'd say she's talking to Christians, not 'everyone'. She wouldn't be able to call anyone a lukewarm Christian unless they're Christians already.
Although I'm not sure she can stand perfectly to say there aren't things she's guilty of (as Jesus said, He who is without sin cast the first stone), she's referring to lukewarm Christians who cherry-pick teachings to follow in the bible (Possibly referring to Christians who have come out as gay). The lukewarm thing is based on a specific scripture and what the general Christian population accept to be real/serious sin or not.
From where I stand though, most Christians are 'lukewarm' in that they cherrypick what to follow or not.
Disclaimer: I don't agree with her views and I don't believe homosexuality is a choice or wrong even IF someone chooses to live as gay person. I didn't think I needed to say it because it's unnecessary but I probably do, so I don't get 'cancelled' 