Is holding a party for a seven-year-old girl to encourage her to pray a correct method for teaching her and instilling in her a love for prayer, or is rewarding her after she has learned more appropriate?

There is no harm in a mother holding a small celebration for her daughter upon reaching the age of seven, to encourage her to pray, because it is not a religious celebration or a recurring holiday. Rather, it falls under the category of customs, the default ruling for which is permissibility. This is considered one of the educational methods that fall within the legitimate means to achieve a Sharia objective, and there is no difference between encouragement before learning to pray or after. It has been authentically reported that the Companions used various means to encourage their children to worship, such as distracting children from food with toys during the fast of Ashura. Finally, there should be no strictness in such matters, lest it cause aversion to religion, for the tolerant Sharia does not prohibit customs unless there is obvious harm in them.