A crown is a very large coin, 39.0 mm 30.0 g and is .925 Silver, 0.8409 oz. ASW.
If the edge inscription is LVII, that's definitely a Crown.
Current CV's in UK£:
Denom Year F VF EF Unc
5s 1894LVII £20 £45 175 £400
The edge inscription (LVII after the date) is the Regnal year, ie the number of years since Victoria came to the throne (1894 - 1837 = 57)
This is a great site for UK coins:http://www.coins-of-the-uk.co.uk/fives.html
A friend is a present you give to yourself.