When a woman is upset or not okay with something, you will know. If they stop talking to talking about it, and it's still not been resolved, then you should get worried.
It could be that she's content with the situation as it is as or the fact that she can't tolerate it anymore and is ready to leave.
Here are some of the signs
1. She doesn't care about what you do anymore
She is used to be concerned about what you're doing or how she can help but suddenly she doesn't seem so interested.
You can do whatever you want and she doesn't even flinch.
2. She talks about how your relationship has become more of work
If for example, you have an argument then she starts talking about how being in the relationship is hard then a split may not be so far away.
3. Every time you have a date, it always has to be around other people
You can't go anywhere just the two of you. She always finds a way to invite some of your couple friends along the date.
4. Your issues go unresolved
She hasn't put any effort into fixing whatever issues the two of you may be having. They keep piling up and she could care less about trying to solve them.