For first main arc, had she not made preparations in advance and figure things out she and the first target will be dead by then without accomplishing anything, (and also midst of it due to that that they avoided certain deaths as well) she's just that intelligent. For the continuous main arc, she even protected the defenseless targets for a short while and fending the boss of the arc all by herself, along with a helpful friend that knows of her circumstances well (saying this advance, the friend knows about it because Erica judged that she will need their help in the future arcs, so no point hiding it from them as they are, in fact, more OP than the targets themselves). As for 3rd main arc.... She literally just handled the situation all by herself with only support from the targets. So the guy that said that she's a Damsel in Distress should really re-read the whole thing. And not to mention she went to put an end to some dangerous situations all by herself too (with the secret friends she made along the way of course).... without anyone knowing, saving the target that provides the stuff she needed. I said till this point but don't misunderstand, the targets are aslo powerful and useful in their own way: up to current arc, 3 of the targets are geniuses in their own league, so it's kinda hard to compare among themselves, not to mention someone like Erica who is someone that is reincarnated.
As I said earlier, she made those deicisions are either she HAS to do so, or that she can't really tell others about it. The example for the first one would be that moment when she is unable to tell others about what happened in the first arc mainly due to
1. She did not expect that in the first place, as she thought she had avoided that from happening in the first place.
2. How the heck can one tell others about the trouble they are in when they themselves are trapped in a space where they are unable to go to others?!
3. Are you telling someone to just stop in their steps of pursuing someone who is about to break down and inform others about the fact first? If you do that, I think that person will be doomed.
4........ Telling others that you sneaked out and explain things that are not supposed to be explained cuz it is related to it all. Yeah, why don't you do that.
As for the latter it would be her circumstances of being a reincarnated being, she chose to tell the friends that she made along the way rather than the powerful targets are because she don't want them to be worried about her; facts about her death flags and if that happened, she won't be able to completely crush the death flag. Why the friends? Well, why not, when they are considered OP, and also the fact that their very being are to be hidden from the knowledge of the public. Of course with that said, she did not completely disclose the information as well; she just kept part of it hidden and fabricated it.
Sorry to disappoint you, but up till the current arc of having 3 targets, not all of them fall for her. One of them just decided to continue become their friends with no romantic feelings involved, at the same time a relationship of benefactor and beneficiary; which to me is really refreshing to be honest. Because in novels such as this, usually the targets ends up being in the harem of the FeMC. So having a pure friendship and at the same time trusted 'business' partner is something that is very new to me.
She stated herself that she is actually very insecure of the scenarios that happens that are out of her knowledge - not as in how her actions will change the scenarios and be unknown to her; the fact that she decided to completely crush the flag into nothingness already imply that she is not worried about the changes to the future, but rather it is actually the fact that she has not cleared the game, not even half of 7 routes. As simple as that.
All that Erica did are to ensure so that the people around won't be dragged into the incident whereby she is supposed to be the victim of it. Yes, she actually placed herself second and put others first. And not to mention, due to what happened in her past life, she's not all that bright about her new life at all. It's to the point the people around her keep telling about how they are unable to figure out what she is thinking at all and how she occassionally showed complicated expressions, despite being 8 years old.
I'm not sure if the word trauma fits the frame, because for Erica, she don't really get close with any people till the incidents happening and by chance she just got close to them. And also, she also don't want to be that involved in romantic relationship as well due to the past, to which it becomes light comedic relief in some occassions.