Friendship is a difficult sibject. St. Francis de Sales in Introduction to the Devout Life discourages freindship with those of low moral character. That certainly includes those living of lifestyle which based and defined by their unrepentant abberant sexual activity.
His reasoning is that people like this tend to drag us down more than we can lift them up.
On the other hand, Ezekiel 3:17-21 admonishes all of us to correct the errors of others. Of course we must do this gently.
So if we avoid these people, how can they learn?
I think there is a great difference between being friendly and friendship. Working together being kind, polite and friendly at work is fine; important even. But look for opportunities to explain “Love the sinner, hate the sin.” Because once a person understands that that is what the Church desires us all to do, it makes talking about other things easier.
Modern secular culture places a higher value on homosexual relationships than it does on normal ones. Thus only a vanishiingly small number people in that lifestyle would ever listen. People like their sin. No one likes to be told their way if life is inherently evil. This is never more true than with gay sex and gay couples.
To me it seems beyond unlikely that any good could come from developing a friendship with her. It is more likely to harm you by poisoning your moral sense and polluting your conscience.