Sometimes matches are just not interested, for whatever reason, although to have had some sort of response from her is a start. Perhaps she only tested for the ethnicity estimate, or she doesn't want to be drawn down a path she doesn't want to know about.
The only other possible way forward I can think about is if there are shared matches between the two of you that may help at least point to the line you are likely connected on, which might point you towards investigating those matches and/or widening and bringing forward that line in your own tree, in the hope it might lead somewhere
There may be all sorts of reasons. It can be frustrating, but if you've tried there may be nothing else you can do, unless another match pops up in the fullness of time that makes everything click into place.
I have my own collection of strange issues: A match who I believed I had identified as a 3C1R. I sent her a message and got an enthusiastic response confirming the relationship. She seemed very keen to know more. I gave her a bit more information in a reply, along with my email address, and suggested that if she let me have her email address, I could send her a copy of my tree, photos and other information. She never replied.
A 2C whose tree was all over the place. We actually met up and I showed him my research and gave him copies of all the relevant BMD certificates and other information. He used some of it, but not it appears, anything that referred to illegitimate ancestors, bigamous marriages or similar issues. He has invented lines still in his tree masking and bypassing those issues.
And another cousin who has a tree on Ancestry that is completely incorrect on our GGF's name and ancestry. Since it appeared it has completely skewed nearly all Thrulines hints on that part of our family. But I'd already sent him copious amounts of information about the correct lineage. When I spoke to him about it, he told me that he knew the tree was wrong, but it had been created for him by a friend, and he doesn't feel that he can change it for want of offending her