This is from the great god OED
mardy, a. dial.
[f. mard a. + -y1.]
Spoilt', sulky, whining. Also as n., a spoilt child.
1903 Eng. Dial. Dict. IV. 34/1 A boy who cries with pain is called by his fellows a _mardy baby'.
1913 D. H. Lawrence Sons & Lovers vi. 127 _Now, Miriam,' said Maurice, _you come an' 'ave a go.' _No,' she cried, shrinking back. _Ha! baby. The mardy-kid!' said her brothers.
1915 ---- Rainbow i. 12 Young Tom, whom he called a mardy baby.
1930 ---- Phoenix II (1968) 170 As for Harold, he was all right. He was very respectable and a bit of a mardy, perhaps_but he was all right.
1959 J. Braine Vodi i. 22 _Don't be so bloody soft, man,' Tom said. _I don't want to go.' _You're mardy. You're dead mardy.'
1961 J. I. M. Stewart Man who won Pools 35 'E were a mardy one as a nipper, our Phil.
1975 D. Clark Premedicated Murder v. 83 _You can get all mardy about it if you like,' said Green, unabashed.