Praise be to Allah.
In order for the ‘aqeeqah or udhiyah to valid, it is not stipulated that the name of the one who is offering the udhiyah or ‘aqeeqah be mentioned over it. It is also not stipulated that they be slaughtered at home; in fact it is acceptable for them to be slaughtered in a country other than the country of the one who is offering the udhiyah or the child for whom the ‘aqeeqah is offered.
What matters is that the one who offers it intends that it be an udhiyah or ‘aqeeqah. It is not stipulated that the slaughterman or butcher be aware that it is an ‘aqeeqah or udhiyah. Based on that, that ram was acceptable as an ‘aqeeqah for your older daughter.
It is not essential to offer a particular type of livestock for the ‘aqeeqah. Either a male or female sheep is acceptable, and so is a lamb or goat. That is because of the general meaning of the words of the Prophet (blessings and peace of Allah be upon him): “For a boy, two sheep, and for a girl, one sheep, and it does not matter whether they are male or female.” Narrated by al-Bukhaari (1516); classed as saheeh by al-Albaani (may Allah have mercy on him) in Saheeh Sunan at-Tirmidhi.
But in the case of the ‘aqeeqah, the same rulings are stipulated as for the udhiyah, that the animal should be free of defects and of the right age.
Ibn Qudaamah (may Allah have mercy on him) said: The same defects should be avoided in the case of [the ‘aqeeqah] as in the case of the udhiyah. To sum up: the rulings on the ‘aqeeqah are the same as the rulings on the udhiyah with regard to the age of the animal, and the same defects are to be avoided … So it is not acceptable to offer anything less than a six-month-old sheep or a one-year-old goat (i.e. it is in its second year), and it is not permissible to offer a one-eyed animal that is obviously one-eyed, or a lame animal that is obviously lame, or a sick animal that is obviously sick, or an extremely emaciated animal, or a mutilated animal that has lost more than half of its ear or horn. End quote from al-Mughni (7/366).
The acceptable age for an ‘aqeeqah is five years in the case of a camel, two years in the case of a cow, one year in the case of a goat and six months in the case of a sheep.
Based on that, you do not have to slaughter that which is most expensive. What matters is that the ‘aqeeqah be an animal that would be acceptable as an udhiyah, meaning that it has reached the right age and that it is free of defects.
The ‘aqeeqah that you are going to offer later, in sha Allah, will only be for the younger daughter. As for the older daughter, we have explained above that the ram that was slaughtered was acceptable for her ‘aqeeqah.
And Allah knows best.