I would say no.
2011 Wimbledon was only her second event since the Australian Open, she was clearly out of shape, still made the fourth round, and then lost to a player she's proven unable to beat even when in good form (2010) and even nearer her peak at the 06 Australian Open. More than possible she'd have replicated her QF performance from the year before had she faced Zvonareva instead.
2012 Wimbledon, the match with Vesnina and her first few doubles rounds were the most obvious examples of Sjogrens Venus we've ever seen. Even Venus' biggest haters watching that first round, commented in the thread afterwards how sad it was to see her so clearly hindered and debilitated on court, and agreed that it was more than just a typical Venus bad day at the office.
The Olympics saw her record 2 good wins in her opening rounds with (up til then) her best performances in the 2012 comeback, and then even in her loss to Kerber she played good tennis, and probably should have won that match but mentally lost it against a tricky player for her, who ended up having her career year to date. Had she won that match, she'd have faced Vika, who she matches up well against, and this question would probably not even have been considered, she could very well have been in a medal match
That being said, as Venus' athleticism and serve has dropped through age/injury/illness, she's no longer quite got the tools that made her and Serena head and shoulders above the others on the lawns, and she is now probably just as potent on a quick hard court where her game has always translated really well anyway.
Still, i'd wager that healthy she's still in the top 3 players on a grass court on her day (along with Kvitova and obviously little sis), i just hope that next year we get to see it, and that Sjogrens doesn't rob us of one last vintage grass court run by Venus as we are running out of time to see it.