BREATHE! Suck in through your nose, breathe deeply, and exhale through your mouth. Do it again and again until you are calm.
You are making mountains out of molehills. Jillions of children before yours have been baptized. Hopefully, jillions more will be baptized before the End of the World.
Only ONE godparent is necessary. If there are two, then there must be one female and one male- no doubling up on genders.
You can use the same person or set of persons for both girls. You can also choose to even complicate this more and give them each 2 different people. But, you’re having trouble finding folks to fill this position as it is.
If you want to ask your husband’s relatives to be godparents, but they live far away- The person or people chosen can send in their paperwork (proof via their own parish that they are practicing Catholics with no impediments) to your parish. If necessary, the chosen ones can also attend any sacramental prep in their own parish. Most parishes like this on real paper, at least faxed, but prefer something in the mail- no email!
Now then- ANYBODY can proxy for them. To proxy means to represent a person.
So, as an example, if you want your husband’s Aunt Ida to be the girls’ godmother; but if Aunt Ida, good Catholic that she is, is off in mission country in darkest Peru, you can have Aunt Ida’s parish or mission send your parish a letter saying Aunt Ida is a practicing Catholic in good standing. Your sister, Marlys, can stand in for Aunt Ida, even if she is Lutheran.
Another way to be inclusive is to have one Catholic godparent and one non-Catholic (Lutheran) as a Christian witness. The non-Catholic in question is not a godparent in the sense the Church means godparent, but stands at the baptistry and witneses the event. It is this person who is listed as Christian witness. As there is only ONE (Catholic) godparent in this instance, there is only ONE Christian witness.
As an another example, your husband’s brother, Gerard, is filling the honors as godparent. Your sister, Marlys, stands beside Gerard as Christian witness, and her name is recorded as Christian witness on the baptismal register.
As to time and place, that is usually governed by your pastor and the parish. I wouldn’t worry about all the Lutherans not going to communion if the girls are baptized at Mass, if that is the normal way to do things in your parish. By this time, the Lutherans have figured out they cannot receive, and if it rankles them that much, well, they can stay home and make jello for the party after (my :twocents: anyway). The emphasis during a baptism is entirely different than the emphasis during a nuptial Mass of a mixed marriage, where one of the happy couple is not receiving comunion. At a Mass where infant baptism is performed, the emphasis is on which baby cried the loudest when the water is poured or when the babies are immersed, and which child has the cutest outfit.