Gräfin Agnes von Wangen - Lineage

https://fmg.ac/Projects/MedLands/BAVARIAN%20NOBILITY.htm

AGNES von Wangen, widow of HEINRICH I Graf von Tirol, daughter of ALBERO [I] von Wangen und Burgeis & his wife --- (-3 Nov ----). The primary source which confirms her parentage and two marriages has not been identified.

is the only source I've been able to find any documentation of this Agnes and it names her father but goes on to state that there is no identified primary source for either her father or her two marriages. No name is given for her mother.

So I first checked the profiles on the lines of her parents and see that there are no profiles notes or sources. I Googled trying to find something and only found a very few personal trees with no sources.

Thanks in advance if anyone has sources to document Agnes' lineage. I don't want to add ancestors to my personal tree for whom there is no validation that they're actually my ancestors and not just unsourced, speculative connections.