Pre-filling the Number of Guests Attending on Rsvp??

Hi Everyone! I have invited some people to my wedding who are not in relationships and I am not giving a plus one based on space restrictions. I am addressing their invitations to just them and not including any "& Guest" or anything.. inside the invitation will be the RSVP card where it has a space for number of guests attending and then either to indicate if they can come or not. My question is, is it rude or acceptable to prefill the number of guests attending on their RSVP card with a 1 to make it clear on the single invites? There are a few people that I could see RSVPing with a guest like a friend or their mother when they are not invited, and I was wondering if it is alright to be proactive about it. Or do I just need to wait and see what happens and address it when it does? I could totally see one person RSVPing for two and bringing her mother, who I didn’t not invite, but I think was expecting an invitation. They will already have friends there so they will know plenty of people.