eBay
There is a lot of money to be earned and good things to be said about eBay. For some it has become a full time, money earning business. You can sell a line of goods with your own e-bay store.

More realistically for a quick cash infusion selling your own stuff would be a great idea. If you are a head of the family you can get everyone to spend time together on evening or weekend afternoon collecting the things that are no longer used or necessary.

You can open an account with e-bay easily if you don't already have one.
I also use PAYPAL to handle my sales as it is safe and easy.

I always make it a point to add the amount to ship the item so as to be sure not to sell something where the shipping charges negate the profit on the sale.

There are some business that sell peoples items for them on e-bay for a percentage of the sale. You might in conversation find out that your friends and relatives have stuff that they don't want and might donate to you. E-bay is like having a yard sale open to the world.

Don't underestimate the power of eBay. People have sold real estate, expensive cars, airplanes, motorcycles, etc.
Some just sell collectibles and make a handy profit. You certainly can make extra money to pay the bills by selling just about anything to anyone in the world. I found it was easier to sell to the USA and avoid the hassle of international shipping.

I did sell an antique banjo to a fella in the UK for a nice profit. I had three and didn't really need it.