The Torah states that there were two midwives who helped the Jewish women give birth, and they were named Shifrah and Pu'ah (שמות א:ט"ו). Rashi there says that Shifrah was a second name for Yocheved, later to be Moshe's mother. She was called Shifrah because of the good things that she did with the babies, as implied by the Hebrew root of the word Shifrah. Puah, moreover, was a second name for Miriam, Moshe's sister. She was called Puah because of the comforting sounds she would make to the babies to pacify them, again, as implied by the Hebrew root of her name.
Rabbi Yerucham Levovitz commented that when the Torah calls someone by a certain name, the name is not random, but rather represents the qualities of that person. The fact that Yocheved and Miriam were referred to by these special names shows that they helped the babies physically and emotionally. It can be seen from here that what might appear to be minor actions can actually indicate an elevated level that can ultimately define the nature of the entire person.
There is no activity and no object which in itself is small or great. Everything depends on the person that is doing the action. The great person will achieve great accomplishments through seemingly minor deeds. The small person, on the other hand, will take precious activities and treat them as insignificant. Rabbi Levovitz adds that deeds may be compared to money. Money can easily be bad for a person, tempting him to become greedy and do all kinds of terrible things. But, on the other hand, it can be great because, with money, one can do many Mitzvos, particularly acts of Chessed. One can reach great levels by using money wisely.
Similarly, the acts performed by a person, depending on how they're done, can bring a person to greatness. In every action of a great person, one can find greatness, even in the smallest things. By playing with the babies and just making a few comforting sounds, Yocheved and Miriam merited reaching the highest levels. They occupy a special place in the Torah as Shifrah and Pu'ah simply because of their kindness to and compassion for babies. Actually, when one shows love and compassion to others, one is emulating Hashem. The greater the act of kindness that one does for others is, the more one becomes elevated himself. When one plays with little children, one is not engaging in something trivial or frivolous, but rather one is emulating Hashem and training the children to grow up with good Middos, and learning to perform acts of love and kindness to others. (adapted from Da'as Torah).