Could do with some opinions.

[Kyle]

Trust her. You're working different hours, probably having less physical contact with eachother and consequently less time to just talk to eachother. What you see as a change in her behaviour could just be tiredness. Set aside one day each week or two for you both to have some personal time together. Go on a date, watch a movie, binge watch a TV show, go paragliding, whatever. Just rid yourselves of any distractions and indulge, enjoy each others company as if you just started dating. Talk to eachother. Naturally having a child can be difficult when arranging this sort of thing but it is important to keep that spark alive, so make the grandparents babysit, they love it.

[Zak]

Trust her.

This might be an obvious one but it needs to be done. My girlfriend does sports massages for athletes from time-to-time and I just let her get on with it. People are likely to hit on her but they're the ones who are going to be drunk, not her. At the end of the day if she is going to cheat on you, she is going to cheat on you - and you don't want to be with someone like that.

[.MiniDan.]

A relationship is based on mutual trust, communication and support. There is no one here that can give you better answers than her. Sit down and talk it out, even if it's awkward, rare, or whatever. If something is not right you need to settle it because if you keep it to yourself you will just make wrong ideas and panoramas that are far away from reality.

Discuss the problem, evaluate the options and decide, but do it together, as a team.