Try workaround with
PBXes.com before you get OBi configured.
• Create Google Voice gateway (gvgw) account on
simonics.com, maybe you need a new Google Voice account.
• Add gvgw as a trunk to PBXes
• Add an Extension, Classical Extension (101), Device Options, PSTN_Number -> your daughters cell phone number
• Add Incoming Route, username-101, Set Destination -> Extension (101)
• Add Outbound Route, gvgw, Set Destination -> Valid for all numbers
• Route UK DID -> sip:username-101@pbxes.com