Astrid & Agnes by Angie is the next step in Angelicas dream panties, They are two different models where Astrid is a string and Agnes a kind of brazilian that cover half of the bottom without getting to much fabric in the front.
The design is drafted to not have a to snug fit, so the selvage in the fabric will last longer.
The sizes come as 1,2,3 and so on, instead of S,M,L or 32,34,36.
The sizes are just as B,Wears other patterns made after non standard measurements so make sure to take your measurement before using Astrid & Agnes by Angie.
You should be able to use the same size as you did when you tried your Sigrid.
You will find the pattern in both paper and PDF.