How to match n number of lines

I have some text like this

Notes:
He jumped the sea-horse
but it looked ropey
Then he left

but sometimes its like this

Notes:




Clay is only green
When it is seen

I need to capture 4 lines of text after "Notes" only so the output should be

Notes:
He jumped the sea-horse
but it looked ropey
Then he left

and for the second example

Notes:

I have tried matching the newlines but it only matches after the rest of the regex

Notes:.*n{4}

How can I create a regex that allows me to repeat the match for the whole line and a newline four times? (is this a non-capturing group??)