I think she's just trying to get her 2 minutes of fame. See the "Part of me doesn't even want to get married now," comment for more confirmation of that!
The airlines don't just kick a group of people off a flight for no reason. There is protocol to go through, and the consequences of having to call police and have someone removed, let alone a group of people, will be lengthy - not to mention the admin thereafter.
They claim they sat down and were then hauled off. Not doing anything but sit down quietly.
The airline claim they were refusing to cover up (there'd most likely be a complaint from other passengers, possibly ones with children, which drew their attention to it) and causing an issue. Apparently asked several times inc by the police.
Sounds to me like they weren't happy to cover up, were called on it, kicked up a fuss and didn't just calmly put a jacket over (bride claims they had jackets when they arrived which they had removed) or change the top (she says they had hand luggage with clothes in) when asked a few times.