First, your english is great so no need for apologies. Now for your question: Only you know her well enough to know if this is something that will make your relationship stronger or weaker. Only you know what you mean by feeling ‘uneasy’ when finding out about her hooking up with other people. If it was too much for you to know that she had any kind of intimacy with others while on a break do you think you’ll feel better about it now that you’re together? I could see it being better because there would be transparency and you can be involved but you mention that she was hesitant to be truthful with you about her being with a friend of yours. I assume that was included in your post because that kind of thing is a part of your hesitation.
Whether or not you’re ready isn’t something that any of us who comment can tell you. I can say from experience that partaking in this can require a great amount of emotional work on your end and requires confidence. Not just confidence in your relationship but your own self confidence as well. I’m amazed all the time that my husband is so open to this fantasy and willing to examine every feeling and thought that comes our way about this kink, even when it’s difficult (especially when it’s difficult). If this is something that is strictly a turn on in the moment and then you have post cum regrets then you don’t have to go as far as her having sex with others for you to enjoy a lot of the aspects of this kink. Maybe taking baby steps towards hotwifing is best so you can check in and evaluate how you feel each step of the way and see what’s working for everyone and what isn’t. Flirting over text with other men and sharing pictures are pretty common first steps…as in camming. You get to be involved in all of those and watch and enjoy her having incredibly sexy experiences with others and sharing in that with you. There’s no rush to make it a reality if you aren’t sure you can handle it. It truly isn’t fair to her if you encourage her before you’re ready and then take it back. It’s emotionally jarring to have that happen and will most likely lead to her feeling quite terrible about the experience.
TL;DR Take baby steps and evaluate how you feel about those before jumping in if you’re feeling unsure about how hard the reality will hit you 🙂