We are both 34 and our girlfriend is 24, the triad is great and yet I keep ethically spiraling

ok so a bit of context first bc this isnt a typical swingers post. me 34, dh 34, married 8 yrs, we started exploring poly about 3 yrs ago after 18 months of swinging that left us both wanting something more relational than recreational. we met our girlfriend 14 months ago at a play party, she came to dinner the following week and just kept coming, and somewhere around month 5 we all said the words out loud. she has her own flat, her own job in research, her own friends. she chose us repeatedly with eyes open. shes 24, we're both 34, the math gives a 10 yr gap. the triad is honestly the happiest relationship structure ive ever been in. we communicate constantly, we have regular check ins, we've done some couples (throuple?) counselling once already to make sure none of us was bottling. by every measurable metric this is working. and yet. like once every few weeks I have this little ethical lurch where I look at her across the kitchen island making coffee and I think "she was 23 when we met, were we already too established as a unit, did she really get a fair shot at being the equal partner here". she's told me directly that she doesnt feel less-than. she set the pace on multiple of our relationship milestones not us. and STILL my brain does the thing. I think part of it is internalised stuff about poly and "unicorn hunting" which I know is the cardinal sin, and part of it is just the math when I see it written down. 24 isnt 18 and shes been in the dating world plenty long enough to know her mind, but the gap PLUS the couple-and-one structure makes me wobble. has anyone else done this kind of triad with an age gap and worked through the ethics out loud. did the spirals go away. or are the spirals actually the sign that im taking it seriously and i shouldnt try to make them stop.