Not too sure how old your toddler is but you can refer to this World Health Organisation chart to see if your daughter is in the healthy weight range.
http://www.who.int/childgrowth/standards/weight_for_age/en/
Generally, if your child is eating well, consistently and there is nothing amiss about her health and behavior, she is most likely fine even with a stagnant weight. My nephew (3 years now) was the same weight for a year plus and suddenly after enrolling in daycare, his weight increased by quite a bit. His mom attributed it to the types of food and snacks he is exposed to at the daycare. Plus he is more active now too.
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