How do we know which needs women can go out for and which they cannot?

It is stated that women should not go out of the house unless there is a need. However, the need referred to in the Hadith was to relieve themselves as there weren’t any inside toilets at that time! There’s also proof that women are allowed to go outside to visit the mosque! But apart from these two examples how do we know that women are allowed to go out to visit friends and family like female cousins even though these might not be considered needs? I read on one websites that women can go to visit their parents often but apart from that they can only go to meet other relatives once or twice a year as more than this is not a need. So if I want to go to visit my female cousins more often like twice or thrice a week, even if it isn’t a need, will this be allowed or will I be sinful for going out without a need?