I would not put suggestions in the invitations. It is already hard to get people to RSVP so that is one way you will know they are coming because they may call you and ask what your child likes or the size she wears. The less you put on the invitation the more info they will need to call you for, then you get an idea of how many are coming. I was amazed at the gifts my kids got for their first birthday. They got some really nice expensive stuff that I would have never thought of buying and sure wouldn't have mentioned items that expensive if they had asked. I have taken several items back without receipts. If I am not sure which store the item came from I will look in the stores and see if they have that item. Some stores may give you a gift card instead of cash because you don't have the receipt but you can still get the items returned and get something else.
I have taught my kids to say thank you for everything even if they already have those items. It is embarrasing when they open a gift and say I already have that and sometimes they will even get the same toy while opening up the gifts and they politely say thank you and cool I got 2 of them, then we will take one of them back later or sometimes one of the gift givers will offer the receipt and say it's ok to take theirs back since they got more than one.
Now that my kids are getting older and so many kids have everything already, I just send money with a card. That way they can compile all their money gifts together and get something they may have been saving up for.
Just enjoy her birthday and you will be surprised at how well everything turns out. You may also be surprised at the cool gifts she will get.