Twin Victories (Heartsong Presents)

is book #370 of the Heartsong Presents line.
==Book Description==
This will be a summer to remember. — Amy Wilkins isn't interested in making her four sons the subjects of a research project. But when an identity mix-up at school deeply upsets her sons, Amy knows her family must participate in Dr. Todd Avery's research project. She sacrifices her jealously-guarded privacy and all her waking hours as a c...  more »hild psychologist invades her family's home and lives for three months.
For Todd, finding a family with two sets of identical twins to study is like striking it rich. Best of all is their attractive mother, whose commitment to her sons and Christian faith touches him at the very core of his soul.
Could it be God has rewarded a mother's personal sacrifice by providing a man to love her and her sons?
"Lo, children are an heritage of the Lord: and the fruit of the womb is his reward. As arrows are in the hand of a mighty man; so are children of the youth. Happy is the man that hath his quiver full of them." (Psalm 127:3-5). 
(Description from paperbackswap.com)