Welcome to YT!
Can't wait for pictures! A very general rule of thumb to get the adult weight is to triple the weight at 8 weeks and double it at 12 weeks. This can give you a vague idea. BTW, I'm also a SAHM with a 13 yr. old daughter.
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"If you have men who will exclude any of God’s creatures from the shelter of compassion and pity, you will have men who will deal likewise with their fellow men." — St. Francis of Assisi, 1181-1226