I think it does: Roger and Mr. Jeffries used remnants of Delphine Courtney to build Heather's suit.
Only if the writer were deliberately trying to do something totally opposite/out-of-character to what had been established. Originally, Heather helped Mac create the team; the Mantlo era repeatedly states that she was just a housewife and had nothing to do with it.What does make a difference is what happened at the same time - the book changed writers. Sorry to harp on the old thing here, but I think she'd have been just as bad, made all the same decisions with or without the suit under Mantlo.
Please! Vindicator killing Snowbird was bad enough. Having somebody else do it...Granted, she wouldn't have killed Snowbird herself (she cannae do it, she doesnae have the power!), but she probably would have made one of the team do it for her.