I don't know how far to go in my relationship with my husband's family.
I don't know exactly how to interact with my husband's relatives.
この場合、次のような言い方ができますよ。
ーI don't know how far to go in my relationship with my husband's family.
「夫の家族との関係をどこまで行けば良いかわからない」=「どこまでの付き合いをして良いかわからない」
ーI don't know exactly how to interact with my husband's relatives.
「夫の親戚とどのように交流して良いかよくわからない」=「どのように付き合って良いかよくわからない」
ご参考まで!
I am not really sure how to manage my relationship with my partner's relatives.
I got married to someone from overseas, so I am not sure how best to deal with my in-laws and their families.
ご質問ありがとうございます。
① "I am not really sure how to manage my relationship with my partner's relatives."=「私のパートナーの親戚とどのように付き合えば良いのかよくわからない。」
② "I got married to someone from overseas,"=「海外の人と私は結婚した」
"so I am not sure how best to deal with my in-laws and their families."=「なので、義理の両親や彼らの家族たちとどのように付き合えばいいのかよく分からない。」
ご参考までに。