I don't think so, as she's on a mixture of long and short acting insulin. Though I guess she could try phoning her clinic to ask for advice? But like you, I'm T1 and I'm not sure that insulin is managed in quite the same way for T2s.
The issue here is whether she is still producing her own insulin. T2s are insulin resistant, so they typically over produce insulin until their insulin producing cells start to wear out... Many T2s can come off insulin altogether if they just reduce their carb levels to what their bodies can cope with.... (Really, it's counter productive to inject insulin to a system that is already overloaded with the stuff, but I don't know whether your sister is still over producing insulin.)
Your sister would have to do this carefully, because of her insulin, but is she open to reducing her carbohydrate intake? That meal would be a bit of a disaster for the T2s on here who successfully stay off medication altogether by going low carb....