Help a Newbie Help His Mom

Here's my deal. I want to share my wi fi with my Mom. She lives next door and the distance between our homes is about 300ft. She will only be using her Kindle to pick up the signal. What should I do to boost my signal so she can access it? I have an extra desktop that I could hookup for her if needed. I just have a basic wireless router. I have a storage building thats closer to her that I could add something there. Like I said I'm a newbie when it comes to wireless networking and I would appreciate any help. Just let me know what equipment I need and what I need to do. My Dad recently passed and I'm trying to get her more technology savy to help pass the time this winter. Thanks in advance.

Hate to be a bother but want to do this for her birthday coming up. Thanks

Well at my place we have to buildings one has a network conected to the internet and in the other building, a computer conected to the network at the other building.
The two buildings are at least 100 meters apart (around 300ft).
There is a network bridger that has a giant range that I use that works like WiFi (my phone can connect to it).
Its powered off PoE so it should work off a basic router as long as it has an ethernet switch (a few ethernet ports on it) and a PoE adator. The areil thing directional and is on the side of the house.
Only thing being it cost like $1500 for the whole set up.

Thanks for the reply. $1500 is out of my price range. Im such a novice when it comes to wireless issues. I'm not computer illiterate but I do admit I'm a dummy when it comes to doing anything in wireless outside of hooking up a wireless router. Is there another option do me? Basically I just need her to be able to access my wifi with her tablet. Would appreciate some more suggestions.

any other suggestions?

You can try a $49 Ubiquiti Loco M2 2.4 GHz radio that can act as a wireless access point, and point it towards her house. 300 feet, she sold be able to get a siganl indoors on the side of her house that faces the radio.