Assuming you are in the UK your will likely be assessed by an orthoptist first.
They are experts in visual development and binocular vision problems.
They will attempt to measure the vision in each eye (to make sure they can see equally well) and also measure the esotropia, how large, one or alternating and try to get an idea if it is there all the time.
Your DD will then be checked for a glasses prescription and the health of the eyes will be checked. This will most likely require the use of eye drops.
The eye drops are very safe, cause a slight stinging censation for around 5 seconds on instillation and take 30mins to work. They don't always work so well on children with very dark eyes.
After this they'll know what needs to be done.
Glasses, likely for long-sightedness (hyperopia) are very commonly prescribed for esotropia. They can help straighten the eyes, improve vision and help avoid a lazy eye (amblyopia).
They may not need to be worn for ever but will, if needed, likely be required for till your DD is 9yrs or so.
If glasses are unsuccessful, or not appropriate, then nothing else needs to be done if both eyes see well and equally.
If one eye starts to see worse, patching may be used to improve the poorer eye.
Surgery may be appropriate to improve the appearance but it doesn't tend to help the vision, so the other stuff needs to be sorted first.
Objectives of treatment is to avoid the onset of a lazy eye and then get a good cosmetic result.
Does that make sense?