If they need(ed) money they should have saved it and just eloped.
My mate (well, the parents paid for the bulk) spent an absolute fortune on his wedding because she wanted all the bells and whistles.
A few years back he said they could have had their mortgage cleared with the money.
The wedding industry is quite insane, I really don't understand how people can justify it. As long as you aren't using it as an excuse to indulge+++ it can be done inexpensively, without resorting to begging.
My view on the request from the bride in OP it is a little complicated. Is she actually asking, or is she saying please don't bring any gifts, but if you feel you must do something then feel free to give us dosh? Is sounds like they aren't exactly having a massive blowout, which conversely actually makes the "Pls gief money" thing not so weird in my eyes. I say this as this is
sort of how we played it, allow me elaborate.
We didn't want gifts, but we knew some family would be very stubborn (for lack of a better term) about wanting to give us something, which is fair enough, so we suggested that if that was the case they could give us a financial gift (exact wording not available in memory). Not all did this, which we were happy about as there's something a little tacky about it if everyone does it, most approached us about arranging part of the day, such as photographer/car/cake etc, something we didn't expect at all. We had a good reason to request this; we are by no means poor, but like many couples we'd lived together years by the time we were married and really couldn't justify asking for objects. If anything we have an abundance of possessions, and at a point they seem to just complicate life and get in the way. The last thing we needed to be doing in the run up to our wedding (I was deployed overseas) was to be using our energy to produce what we would have considered to be a contrived list of expensive gifts we didn't actually want. Taking it as an opportunity to let people buy us things that are more expensive than we would normally justify is illogical and simply against our principles. In the same vain, we couldn't justify a gratuitously expensive wedding, so by making sure we kept headcount low (just family) and going for the "please no gifts" strategy, we managed to hold it at a nice enough place, known by the family, with guests chipping in in ways they wanted - but did not feel obliged - to, and still ended up in the black. Going full brain off and childishly holding a irresponsibly large and lavish wedding way beyond one's means is just nuts to me, and I would definitely baulk at being asked to contribute financially to such an occasion. A small wedding... not so much, I'd see it as a direct gift to the couple, for their future, not offsetting (and somewhat justifying!) the debt they're putting themselves in for this one day. I'm not going to pretend this isn't a judgemental response of someone's choices on my part, it absolutely is. There's something about someone throwing a big spectacle of a wedding and then asking for cash that is weird to me.
:Edit: then again, for an evening thing... It does feel a bit rich asking for gifts for just being invited to that. I wouldn't have mentioned it at all to anyone coming to an evening thing (if we'd had thrown one), just the people I know are going to feel like they're obliged through tradition to the main day.