Sleeping adverbs are provided in this article. The words listed here are commonly found along with the verb sleeping in sentences. This reference page helps answer the question what are some adverbs that describe or modify the verb SLEEPING.
actually, apparently, badly, barely, calmly
comfortably, contentedly, deeply, finally, fitfully
hardly, heavily, lightly, merely, mostly
peacefully, poorly, probably, profoundly, quietly
really, restlessly, softly, soundly, sweetly
tranquilly
Hope this word list had the sleeping adverb you were looking for. In addition to adverbs used with sleeping, other example verb adverb pairings can be found on this site.
You can help by adding more adverbs in the comments. Thanks.