Worried about a friend

I work with this girl in work. She is beautiful, funny, caring but there are things that she says that seem off. I know she suffers from depression and anxiety as she told me in passing.
When I first met her 18 months ago she was going out with her friends the whole time at weekends. This week she told me her parents are going out of country for holidays and she alone in the house. I joked she will probably have a house party. Said she not like that and doesn't have a social life. She recently moved into a new home and now the landlord is actively looking for a buyer.
She is always talking and laughing to everyone but I'm thinking she's not ok. Last week she told us she likes to go on holidays and hill walking. She said people are always telling her to find someone to do stuff with. She goes to concerts with her mom and enjoys her moms company. She once told us when her mom was 16 she represented her country, at underage athletics, and that she had not done anything like that.
Looking back she seems a bit down at times but still shows happiness outside.
I know I've only know here for a short time but I see so much of me in her. I've been battling depression and anxiety for years and this instances send a red flag to me. I want to talk to her about them and make sure she ok and that she knows I'm there for her if ever/whenever she needs. Advice please