Since she'll be traveling between two EU member countries (Romania and France), the formalities will be minimal. Assuming that she has Romanian citizenship, she has the right to travel freely inside the EU. She needs to have a valid passport or identity card. Unless something really unusual happens (e.g. her papers are damaged, her name matches that of a wanted person), the immigration officer will look at her ID, maybe check the number against his database of wanted persons, check that the photo isn't too far off, and wave her through.
This even goes if she's traveling via a non-EU member (e.g. a flight via Istanbul) — EU citizens have no formality to accomplish when entering the EU.
If she is Moldovan (or other non-EU/EEA nationality), she will have to satisfy the immigration officer. She should have any invitation letter or whatever papers are required ready, as well as something to show that she has a flight out booked, and possibly a printout of “I'm visiting my family who lives at this address”. But don't worry: immigration officiers are used to people who don't speak the local language.
Going from the plane to the luggage carousel should be self-explanatory. The only potential difficulty would be joining the right queue (automated gates, EU, other) and there'll be someone to wave her into the proper lane.
The difficulty starts when she exits into the public zone. There, there will be signs in French and English only, and any audio announcements in the trains will be in French only. It would be best if someone can meet her at the airport. Failing that, she should either take a taxi (with her destination printed out) or know exactly what signs to follow and what tickets to buy for public transport.