Hello,Barbara! Sorry for the lost of your friend! I guess she was not old but ill...
About your coin: for sure it is a spanish cob coin. It is medieval but exactly I can't say... If genuine... that's another problem... it must be made of silver. From photos I cannot say but you may verify if it doesn't stick to a magnet. Then it will be more likely to be genuine. And,if so,it is collectable and quite valuable
Yes. It is a Spanish colonial cob coin. But, to me, it looks fake.
For a thorough description of these coins, and other coins which are their "cousins," see this page:
The page above has pictures of genuine cob coins. Scroll down to the bottom part of the page. You can see that yours looks different.
As Andi says, take it to a jeweler and have it tested for silver content. If it's not silver, it's fake. Fakes are worth zero.
The information of the coin is as follows: Crowned shield Cob coin 1576-1586 from Mexico (Unknown assayer) It could be 1 or 2 Reales, depending of the weight. Don't understand why it is countermarked with a C on top of the lower left lion, and apparently the same on top of the top right Lion as well.