"Whether those are deducted on C or E probably doesn't matter as the losses will be deductible (due to her RE professional status with the election for a single activity.)"

Of course it matters. It still isn't clear if she was an RE professional or is trying to be an RE professional. There have been lots of discussions on the difference between the tax phrase "passive or nonpassive income" and the actions of passive or nonpassive. The words are not used the same in tax prep vs reality.

You didn't note if she is "investing" to buy and rehab and sell = flipping. Or, buy and operate as constant turnover (short term stays). Or, buy and get residential tenants in (hopefully, long term and stable). Or, commercial tenants.

Sched C is meant to show they are operating a business. Sched E is meant to show they own and rent real property for income. Sched C has a reality check that includes providing services, such as hotel, B&B, perhaps having staff. Making LLCs is just like baking dog biscuits to keep on hand. It's an entity, not an operation.