middle names trouble

stick with me bit of a cofussle. so if we have a boy its middle name will be anthony its my partner middle name my fathers his father so work out perfectly. The girl one gets complicated so my middle name is maree my partners mum and his sister are the same different spelling tho so i didnt want to give our first born to have it as as felt it was bit unfair to include his side and not really mine so im contemplating a double of anne-maree but here is where it gets fun so by adding anne it includes my younger sister and mum and as before maree includes his mum and sister and well me, but i have an older sister and she would really in a way be the only one excluded lately our relationship has been horrible she didnt congratulated me on my engagement or the the announcement of this baby and hasnt spoken to me since christmas but like all sisters eventually im sure will get over it but doesnt help me with middle name do i just find a different name altogether or not worry about how she l will react any help b great