This cartoon by Paul Thomas from The Daily Express blends the 60th anniversary of the Queen's accession to the throne with the snowy weather currently sweeping across Britain.
The Queen is building a snowman. She has put her crown on the snowman's head. Prince Philip comments to Prince Charles, "Your mother's had that crown for 60 years—she'll do what she likes with it!"
1. Note the construction present perfect + for + period of time, used to refer to an action which began in the past and continues into the present. More examples:
• She's (has) known him for 6 months (since July).
• I've lived in France for 30 years (since 1981).
• They've been married for 15 years (since 1997).
2. She'll is a contraction of she will. 'Will' is used here referring to the present to express willingness or desire. Compare: I will get my way. See here and here for more uses of 'will'.