One soon to make a bloomer got up and sat on friend (7)
I believe the answer is:
rosebud
'one soon to make a bloomer' is the definition.
(a rosebud will soon bloom into a flower)
'got up and sat on friend' is the wordplay.
'got up' becomes 'rose' (I've seen this before).
'and' means one lot of letters go next to another.
'sat on friend' becomes 'bud' (I am not sure about this - if you are sure you should believe this answer much more).
'rose'+'bud'='ROSEBUD'
(Other definitions for rosebud that I've seen before include "Flower not yet open" , "Unopened flower - pretty young woman" , "one with potential to bloom" , "Partially-opened flower" , "Partly opened flower" .)