I am a Frequent Flyer with Ryanair and it is, what it is. Cheap. Crap. Gets you there.
If at all possible, check in on-line: you can do this up to 14 days in advance, so you mights be able to do both flights before you leave if you are away for less than 2 weeks.
We fly with 4 children and have totally given up on paying extra for the pre-boarding nonsense as everybody seems to have got it, so it is not actually an advantage as there are so many passengers expecting to be boarded first. Most people, when they hear see us coming, step back
.
Deffo, have your own food and drink and snackes and sweets with you.
IME, you are very likely to get seats together. It is often worthwhile boarding through the back door as less people go there and you are more likely to have a choice of seats/rows.
If you have to have an under 2 on your lap for take-off and landing, it is worthwhile sitting her between you and DH during boarind and unless the flight is totally booked there is every chance that seat will remain empty
[ruthless].
IME flight attendents are friendly and professional, but don't exactly fall over themselves to help you.
Yy, Ryanair is very strict re weight/size limits of checked-in and carry-on luggage. If your DD is over 2 she will have her own baggage allowance of course.
Good luck!