Hi OP,
Congratulations on your wedding!!
If my friend had unusual circumstances that meant they had bare cupboards I would do them a grocery shop and drop it in or if due to unusual circumstances they could not get their child shoes for the new term and they had outgrown their old ones I would give them the £15 for a bargain pair at e.g. Matalan. No payment would be required for these small gestures assuming this was out of the ordinary.
However the next step is supporting your friend with the benefits office/CAB/ national debt line etc to get a longer term solution in place.
If The problem is debt/ lack of bond for a property etc etc you can help your friend fund a solution that does not involve borrowing money. E.g. find Council help or find agents that offer the new no deposit pat an insurance in the rent scheme instead.
It is very suspicious that your friend heard you had some money and immediately needed some. Some people do work this way unfortunately.
I had a friend who when she found out her boyfriend had substantial savings (around 9k I think) immediately wanted to "borrow" it for something. Not something essential - a definite want not a need. She accused him of being selfish/tight/not trusting her to not "lend" it.
We we're only young and he was doing unskilled labour at the time. I pointed out that that money represented probably six months of his literal hard labour and I absolutely agreed he should not just give it to her to buy something. Not a popular opinion with her! Some people are unbelievable.
In short help your friend if you can with advice and support not vast amounts of money. Although if £50 sorts out her issues just give it no strings and avoid the whole lending situation.
As everyone has said DO NOT BE GUARANTOR EVER this is only suitable if you are happy to pay the lot e.g. a parent with a kid at uni guaranteeing their accommodation otherwise no. They have poor credit for a reason!