How can I get rid of this in FB chat?

[elizabeth]

I use FB sometimes in laptop, most of the time its in my phone, where I have FB and FB messenger apps installed.
Whenever my sister uses my laptop to check her fb the chat window says ´online 1 min ago´, even tho Im not using fb in my phone.
I never log off, i just close the application, hate to type my email and password all the time.
So my question is , do i have to log out all the time?, why some ppl just show their cell icon besides their name but doesnt show when they were online last?
Pisses me off that ppl can see when Im online.
and whenever im in fb im never online in chat. . Still this appears.. every.single.time. HELP
Even if i do that, people still can see I was online 1 min ago, or 5 or 11 or 22 .. Doesnt matter, they just dont see the green dot besides my name. they just see a tiny cell phone and when I was online. Also, as I just said before, im always offline chat.

[manish kevre]

You can always become invisible to certain people if you want ..
or can turn off chat completely for all.

use advance setting of chat : just below main chat window towards bottom there is a gear sign button
click it.
then it will give you three simple options
1.turn off chat for all except :
2:turn off chat for only some friends:
3:turn off chat:

all are self explanatory choose what you want.

[kyle]

^

[anonymous]

I dont know