My personal opinion is that anything goes between two adults, as long as they both consent to it. So if you're both enjoying it and you're ok with the direction your sex life is taking, I really don't see the problem. However, there would be a problem if either of you started feeling as if there was something 'missing' by using toys more than having actual sexual intercourse. There, communication is the key. You say you're unsure if she's happy with how your sex life is going...so why not ask her? Have a frank discussion with her and if she shares your uncertainty, then cool off with the toys for a bit. If not, why worry? Just enjoy!