Sexual compatability is important to the health of a relationship, but it is only a part of what makes a fulfilling relationship.
My current partner is also not ticklish, but she acts for me. On some level I know it's fake, but pinning her down, watching her squirm, hearing her laugh, that's all I need to cum.
At first when I mentioned my fetish, she was also receptive and willing, but we were both quickly disappointed when she couldn't feel much. I tried tickling her everywhere with all sorts of things, never got much more than a little twitching, so eventually she offered to fake it. It started pretty bad, but I communicated like how to make it more realistic and it took some sessions but she's pretty good at it now.
Communication and time to learn and change are super needed in a long term relationship, for everything. Her willing to work on that acting for me is just one of the many ways we support each other. I believed in working something out, because I truely love my partner