Why She’s Ignoring You
The following are some of the main reasons why she’s ignoring you
Turned Off
Some of your recent actions might have turned her off. When you first get into a relationship she might ignore some of your flaws. But as the relationship progresses and they become more apparent, they might have turned her off.
You might be insecure, texting way too much, more invested than her, too protective, jealous, or something else. No matter what it is, she’s lost a lot of interest and is going to start ignoring you.
This leads on to the next point.
No Longer Interested
Because she’s been turned off, she might not be interested in you anymore. Your actions turned her off and now she’s looking elsewhere.
She Met Another Guy
Unless you are exclusive, most people date multiple partners. Honestly she might have met a better man. It sucks, but it’s part of dating.

She Has Too Much Power In The Relationship
If you aren’t dominant in a relationship, she is going to slowly control it. The power will shift from being neutral into her control. If this is the case, she doesn’t need to text you back.
She is conflicted about how she feels
If it’s early in the relationship, she might not know how she really feels about you. Physically, she might be attracted to you, but your actions & behavior might not click with her. She’s not turned off, but at the same time, she’s not attracted to you.
She’s Busy
Unless you have been in a long term relationship, she really doesn’t need to respond to you right away. She has a life also. She has friends, activites, school or work. It shouldn’t be a priority to get a text back right away.

Something came up
She might be sick, had a relative pass away, got depressed over something, or who knows what. The thing is, she’s not in the mood to talk to you at the moment and needs time alone.
Texting Isn’t Important
Texting really should be for minor communication and setting up dates. Find out what happened during the week or day on a date, not over text.
She might have the same views as that and ignore you to send a signal.

How To Fix The Problem
So there are 3 options to rectify the situation
Give her space
Don’t text her for a few days. She’s going to wonder why you never reached out back to her and message you once again.
If you double or triple text her, you are going to look needy.
Break Up With Her
If you really think she’s ignoring you, and you don’t like it, you don’t have to stay together. Break up with her and find a new girl
Talk to her about it
If you’ve been in a relationship for a while, talk to her about it. Something might have come up and it’s out of her control.