Hi<br/><br/>Her mother, <b>being such an attentive person</b>, spotted this at once.<br/><br/>Is the bracketed part in bold an adverbial(participle) supplementive clause? I think so.<br/><br/>Or is it a gerund clause? I do not think so, because we do not make recourse to whiz deletion with non-restrictive relative clauses.<br/><br/>You agree?<br/><br/>Thanks.