Not really. Purugly have a strong fondness for being pampered, so anything you give them that makes them feel like they’re being doted upon are things they’re not going to part with anytime soon. Likewise, purugly can be a bit lazy when pampered (at the risk of putting it too bluntly), so it’s perfectly understandable that she might react this way. It’s not something you did wrong, of course. It’s just in a purugly’s usual nature to lounge with prized possessions, especially as they get older. So long as she’s moving at all and so long as you don’t keep the electric blanket turned on all the time, she should be fine.
In fact, considering the fact that it’s spring for you, she may discard the blanket as the weather grows warmer and she grows more and more uncomfortable with it. Just be warned that she may begin begging for some sort of replacement if that happens, and contrary to popular belief, electric fans, air conditioners, and kiddie pools are not suitable replacements.