Rohan, We can not say for sure whether she is giving you signals or is interested on you or not! Its upto your personal judgement. You are an experienced man having a girlfriend with whom you indulge in sexual relations. So use your experience and take decision about it.
And wearing low cut top, and showing a boob etc i do not think would have been intentional 100% . It could have been a co-incidence.
Another point is most men like to believe that if a husband's job involves tours and travelling , the wife must have been missing sex part very much.Its not true will all the women and many can remain content with what they get from their hubbies. So its upto you.You should make her aware of your interest in her. Praise her . Tell her you like mature women than that of the girls of your age with reasons. (in case she asks for reason/s you should have them ready) But also remember that she is a married woman and if she objects and complains to her husband/ cops your life will be ruined. Take this as disclaimer too as only you would be responsible for your actions.
Multiple answering is not allowed!
It might be your mere observations that she is enduring giving you signals to be intimate with you as there was no direct hint from her yet. Therefore, it is perilous to follow her without confirming her interest in you.
However, there are full chances that she seems interested in you. Since she has an internet connection in her home so she must be having FB account hence, send a friend request to her and start chatting with her. Slowly and steadily, start flirting with her. Her responses will give clear picture about her interest in you.