The only time I’ve seen guests sit on bride/groom sides is when they are seated that way by ushers, IME if guests are left to seat themselves they sit wherever and the sides balance out naturally, like everyone else said. And FWIW I’m thinking mostly of traditional church weddings. At the front of church the immediate families make take right and left side, but regular guests who are not part of the procession sit where there’s a space. So another vote that it’s really not worth worrying about unless maybe it’s a really strict tradition in her community … in which case, eh, I’m sure people have seen it before and will just assume the bride has a bigger family, it’s not a reflection on the groom.
That said, if it’s really bothering her then maybe you could get there 20 minutes early and sit on the groom’s side, and just wave and say hi to people as they come in, and enough of bride’s guests will walk over to greet you and sit near you to cause a natural scatter. (Also I highly doubt the bride will actually notice where everyone is seated during the procession and ceremony, all you really need to do is convince her not to worry about this during the months/days/hours before the wedding)
Thanks for all the assists, everyone! Frankly, (and this doesn’t make me look good) I only thought about ushers managing as I was typing the OP. I really appreciate the help.
MeanJoe, I actually think that what you posted is what they’re looking for. It will be a very country wedding.
I was at a wedding once where there was an extreme case like this. There were about 1000 guests, and the vast majority were on the bride’s side. (The father of the bride was a prominent New York rabbi, and he invited everyone in his congregation.). I was on the groom’s side.
For the ceremony we just sat wherever, which meant that our family was an island surrounded by others. For the reception we took up two or three tables, the bride’s side took up all the rest.
That was something, let me tell you! And before anyone asks, the couple is still together, they have four children, the youngest one is now 14.