Pants are not generally regarded as men's clothing. When Adam and Eve talked to God, they wore nothing. After that, they [mankind] wore animal skins, and eventually some kind of robe, from somewhere before Moses to after Jesus. Then, finally very recently, in AD, men wore pants and women wore dresses, until quite recently in the last 100 years, when it became more practical for women to also wear pants. But to church? I personally will wear a skirt or dress to respect God, as they are still thought of as more formal. But I don't think any lady who wears jeans is any less of a Christian than me, or that it is a sign of dissrespect.