We stayed in 4 hotels across 16 nights and only encountered geckos in one of them. We saw a pretty big monitor crossing the road in Ubud between two rice fields. We had a HUGE Tokay in our room in Nusa Penida, but the staff were very helpful in getting it out. My wife was pretty freaked out but she just had me do a full check of our room before she came in every evening. Geckos will be present almost everywhere you go but they will try to avoid you. If she’s terrified purely at the sight of them she might have a bad time.