I'm a 21 years old guy who's been going to local gym regularly.
Recently, I noticed this lady coming to gym around the same time with her son. She's probably in her 30s, reasonably fit, and most likely a Hispanic. She almost always speaks Spanish with her son, who is around 10 or younger.
She teaches him how to use the machines, etc. He's kind of clumsy at it, obviously. I just smile, because it reminds me of my childhood, sometimes she looks at me smiling, she lightly smiles back.
I'd like to get to know her, and see where we can go. Being friends, casual dating, or even casual sex. I speak fluent Spnaish, so communication shouldn't matter.

And don't worry, I'll only try my chance if she's a single mom. If she tells me that she's married, has a boyfriend, etc, then I'm going to back off right away.
How do I approach her without making obvious that I'm hitting on her?