Which sentence is better to use when someone is using internet?
1-She is connected to the internet.
2-She went on the internet.
Is there any other sentence which suits this situation better than these two?
In addition to Davy's comments, I think that 1 could also mean that she has a connection but that she might not actually be online.
Just a small piece of information -
by convention, the "i" is capital in "Internet"
when referring to the Internet
we are using now to connect to
this website. An "internet"
(lower case "i") can be a collection of
internal networks within an organization.
"Network. Anything reticulated or decussated at equal distances, with interstices between the intersections." - Samuel Johnson