Yes, selective hearing is a long-term thing.
We have that problem here, too... I hardly ever use "come"...but when I use it, I MEAN it, and Denna knows there is no arguing with it... we have a more casual "com'ere" command for use around the house, in order to reserve "come" for official business, so to speak.
The biggest thing about "come" is that you can NEVER use it to call her to you for a punishment - that means no "Come, get in your crate so I can leave", no "Come, so I can put on your leash and we can leave the park", no "Come, get away from that dog"... Come must ALWAYS mean "Come get LOVE and PRAISE and COOKIES". Or at least 99.5% of the time. If you want to be able to use it for the other reasons that other 0.5% of the time, you need to increase how often you use it for all the good stuff. Keep pots of treats all over the house, and randomly call her to "come" and give her a cookie. Then, let her be about her business. You can mix in just love and praise with the treats, randomly, too...
Also, don't let her ignore you. When you say "come" everything else stops until she is next to you in the proper "come" location (what ever YOU decide that location is).
There are games you can play to make "come" a habit and basically a muscle memory reaction. The more you practice good "come" behavior, and reward it well, the better it will be in all situations.
It's a life-long job to keep "come" being a good, reliable command. Keep it fun and that will help a LOT.
And... she's a cutie! Love the brindles (I may be biased).