The Collaborative International Dictionary of English v.0.48:

Ungrudging \Ungrudging\
   See grudging.

WordNet (r) 3.0 (2006):

ungrudging
    adj 1: without envy or reluctance; "ungrudging admiration"

Moby Thesaurus II by Grady Ward, 1.0:

57 Moby Thesaurus words for "ungrudging":
   accordant, acquiescent, affirmative, agreeable, agreeing,
   approving, assenting, bighearted, bounteous, bountiful, compliable,
   compliant, consentient, consenting, content, eager, endorsing,
   favorable, free, freehanded, freehearted, generous, giving,
   gracious, greathearted, handsome, hospitable, large, largehearted,
   lavish, liberal, magnanimous, munificent, nothing loath, open,
   openhanded, openhearted, permissive, princely, profuse, prompt,
   ratifying, ready, sanctioning, stintless, submissive, unaverse,
   ungrumbling, unloath, unrefusing, unreluctant, unselfish,
   unshrinking, unsparing, unstinted, unstinting, willing