I can relate this to how a couple might discuss baby names. Names we like and dislike are very personal and reflect so many of our values and identities. If you carelessly shoot down a name your partner suggestions it can sometimes feel to them like a personal insult or rejection. So I can understand you seeking gentle ways to let your grandmother know [name_u]June[/name_u] isn’t top of your baby names list.
Personally makes me think of doom, sand dunes, junior. I would not commit to any name and to try to prevent it seeming like I would definitely use it, I would bring up lots of factors that make you doubt it as a good option. Like ok you will keep it in mind but it isn’t quite perfect for me because of this or that unchangeable reason you cant get past.
It sounds like to preserve the relationship the real reason isn’t one you want to bring up with her. I think even if it was an honour name you did intend to use, there would still be situations that could make it unusable.
Sure you would ‘love’ to use [name_u]June[/name_u] but your grandmother would understand your future partner has a say in the name also so if you eventually can’t get them to agree your grandmother would have to understand right?( I mean your cousin didnt use june despite expectations. In fact it sounds like your grandmother didn’t use it when she had her chance to name her own children!)
Some names you might not be able to get past because of a bad association? Perhaps you would ‘love’ to use [name_u]June[/name_u] but it is your partners ex girlfriends name or a bad boss or unsavory character from a show? And this association has spoilt it regardless that it is an important family honour and you just cant get past it.( Makes you think of the handmaid tale or mama june?)
Perhaps for you children are a while away so you get a cat or dog you name [name_u]Juniper[/name_u] and later find you now just cannot use [name_u]June[/name_u] for your baby. [name_u]Or[/name_u] a ‘friend’ who desperately wants to reserve it and you are now hesitant about having it too committed to your list when rhey are likely to have children first.
Perhaps you begin to feel Month names like [name_f]May[/name_f], [name_u]June[/name_u], [name_f]April[/name_f] and [name_u]August[/name_u] are cheesey? [name_u]Or[/name_u] only acceptable if baby arrives in that month?Or you want to use may and if you have a may/mae and a june it would be too silly?
I understand it would be an honour name but if it isn’t your style perhaps that is a reason to let her know you’re hesitant? like you might prefer something more frilly or unconventional or irish for example? Perhaps it sounds too old lady to you and you find it hard to shake that image? [name_u]Or[/name_u] you have a pattern or theme going with the middle names and it doesn’t fit with your other sibling options? Your last name or your partner might have a one syllable surname which makes the flow terrible with one syllable june?
[name_u]Or[/name_u] you have other honour names that trump your great grandma? So you have your friend’s name, but what about wanting to use your grandmothers name(or mothers or your middle name or your partners family or the city you honeymooned or your favourite food) instead? Sorry grandma, maybe june might not get used unless you have 7 daughters and use up ALL your other favourites first? Sooo many favourite names that you don’t want to decide just yet
[name_u]Or[/name_u] you could talk about your worry if you start using honour names that it sets precedence, lots of people might have an expectation of being honoured also or hurt that they were not honoured or feel favouritism is being given. Maybe you want to avoid all together?
Perhaps she would understand if you instead used jane, jean, jade, joan, [name_u]Juniper[/name_u], jude, luna and you pretend it is loosely honouring? Could be bad as a first name to be always asked if you were born in june?
And really, you could even plan to name your baby [name_u]June[/name_u] and she could be born and you look at her and she just doesn’t LOOK like a june!