Re: What do you think about these names and combos (long)? + suggestions
Lucy Katherine is cute and substantial, so it would age wonderfully, and you both like it. Have you considered using two middle names? Lucy Katherine Grace is lovely!
I also like Lilah Grace or Lilah Katherine.
I agree with you about Grace being a filler name, but I only feel this way when it's used as a mn. As a first name, I think Grace (and even other filler middle names like Marie, Lynn or Rose) are fine. If you agreed to use Grace as a fn, maybe your SO would consider pairing it with one of your less common suggestions as a mn:
Grace Bridget
Grace Magdalen
Grace Xanthe
Another suggestion: Are you stuck on using Avery as a male mn or would you use it for a girl? Avery Grace is adorable.