It probably is, because the only one likely to do any eating of the other is Alida and she'd really rather not. I think I assaulted the night store clerk is not the sort of phonecall she wants to make to Marc right now. "Thank you!" Possibly it would. Possibly Alida would not realize this either way.
She makes her way to said back corner and finds the Schwepp's (Canada Dry is not very sweet) and if she's going to do the thing of bothering to eat she might as well get something she likes the taste of.
Back to the counter she goes, setting the small glass bottle down. "Is it terribly boring to work a job like this?" She's also trying to figure out what he is, but her not breathing and thinking about various and sundry things revolving around blood might give him a hint.